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Pic mcu ice speed governor ..

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lurkepus

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Hi
I'm currently working on a project where i'm going to use a regular car engine to run a genset.
Since the engine comes without a rev governor i have been looking to see if there are a way to make one
using a PIC MCU .

I was thinking about using a flyweel sensor to count the revs and some kind of acctuator for trottle controll.

when it comes to the sensors and acctuator i'm not really sure what type to use but i was thinking about using a PIC 16F628A

Any ideas or links ???

I also need some ideas on the programming part but first i need to gather the parts for the governor
 
Thanks for the link Alec .. It gave me a few ideas .. i have to see if i can get hold of som RC servo units and find a way to controll it with a PIC ..
 
i have to see if i can get hold of som RC servo units and find a way to controll it with a PIC ..
The RC modelling fraternity are doing it all the time, so an RC forum might be better able to help you there. Servos are available for only a few $ online. Basically, the PIC needs to generate pulses of (IIRC) 1ms to 2ms width every 25ms or so. Pulse width controls servo position.
 
Nice controller. That stepper motor/leadscrew assembly looks powerful. If you prefer that to a servo and can make do with a less powerful one you might find one in a scrap disk drive or printer.
 
If you remove the throttle return spring from the throttle flap on the carb it will take almost zero effort to turn the throttle, so it should not need a very powerful servo device. :)
 
I was thinking of doing something similar to what you are. What I wanted to do though was replace the physical governor of a simple Briggs&Stratton like motor with an entirely electronic version. Just for fun really, seemed like it would be entertaining. I'll give you what I got so far.

Edit: Code is in post below this one. :)

As for a sensor, I have a VERY reliable no contact magnetic sensor design that can be made out of just a nail, a rare earth magnet, a bunch of fine wire, and a comparator, and some heat shrink. Really simple and effective actually, it's even water proof. I'll see if I can dig up the thing and post pictures. It's a lot like a guitar pickup. I made it for counting bicycle spokes. Can easily be adapted to count almost any periodic ferromagnetic structure though.


A minor word of warning, using DIY electronics to control large machines can be quite dangerous. One mistake, and *POOF*... no more fingers, arm, life.
 
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Below is my servo code, I found it cleverly hidden in a thermostat project I was working on once upon a time.

Some notes:
I am providing this code to you as a reference, not as a plug-and-play solution to your problem. It may work for you as is, or you may need to modify it heavily to fit your needs. Only you can figure that out. You can probably receive help here on the forms if you run into problems.

I designed this code to make one (or more) out of up to 8 servos quickly go to a single position. It wasn't made to move anyone servo smoothly. If you need to change this, you will need to remove the part of code that loops the main routine X10 times, then just update "position" with a number and call "servo" again and again and again.

This code also doesn't hold the servos position "with authority", instead it lets friction hold them in place. But "position" can be loaded with the same value over and over again, and will need to be if you want it to hold position under power. If the pulse train to the servo control wire stops, most (cheap) servos will relax, and can be moved fairly easily. For many things, this doesn't actually matter.

Sometimes, your servo will not like to have 1ms or lower for fully counterclockwise. When this happens, increase the third literal in this routine a bit. About .120 was good for a lot of the servos I tested.

This was hard coded with a 20Mhz clock in mind. Needless to say, none of the timings will be right with a different system clock.

The meager resolution of just 100 steps was fine for what I needed. You could easily increase this by modifying the delay routines to take ~256 steps per ms instead.

Finally, you will of course need to set up your PIC yourself, outside of these routines. What I have provided is only the routines for controlling servos through a PORTB pin and the necessary delays to do that. It does nothing else.


Code:
;==============================;
; Subroutine to service servos ;
;==========================================================================================
; This routine is used to control basic RC servos. You first load "channel"
; with the bit mask of the specific bit, and thus, specific servo you want 
; to move. Then, you load position with where you want it to move to. Then
; You call "servo" and this routine does the rest.
;
; In practice, it will look like this...
;
;		~Code~
;------------------------------------------------------------------------------
;	movlw b'00000001'	; Which bit of the port is    
;	movwf channel		; the servo control wire on?  (here, we have bit0)
;
;	movlw .50		; What angle to move it to?   
;	movwf position		; 0 > X > 100		     (here, we have ~center)
;
;	call servo
;------------------------------------------------------------------------------
; And here are the variables you need to make it work.
;
;	; Delay vars
;		count
;		count1
;	; Servo vars
;		settle
;		channel
;		position
;
;==========================================================================================
;{
servo	
		movlw	.10			; we need to loop this subroutine enough 
		movwf	settle			; times to make the servo "get the message"

loop	
		movlw 	.200			; Delay for ~20ms
		call	delay_x00us		; 

		movlw 	channel			; Use a bit mask to select 
		movwf 	PORTB			; Which particular servo to move.

		movlw	.100			; Delay for 1ms with 
		call delay_x0us			; pin at logic HIGH(1)

		movwf 	position		; Where to move the platters	
		call	delay_x0us		; 

		clrf	PORTB			; Clear PORTB, ending the pulse.

		decfsz 	settle, 1		; Loop for ~1 second so the
		goto	loop			; servos have time to settle in

	RETURN
;}
;===========================================================================================


; Delay in hundreds of microseconds ;{;=====================================================
delay_x00us	
		movwf 	count1		; Load Counter from working then increment	
		incf	count1, 1	; it ounce to correct a blank value roll over	

		call 	delay_100us	;									
					; Call 100us delay routine, count # of times
		decfsz 	count1,f 	; 									
		goto 	$ -2		;

		bcf 	STATUS, RP0	; Access bank 0									
	return 				; return from subroutine	;}				
;===========================================================================================

; Delay in tens of microseconds ;{ 	; Call = (2 Cycles) ====================================
delay_x0us	
		movwf 	count1		; Load Counter from working then increment	
		incf	count1, 1 	; it once to correct a blank value roll over	

		call 	delay_10us 	;									
					;  Call 10us delay routine, count # of times
		decfsz 	count1,f 	; 									
		goto 	$ -2		;	
											
		bcf 	STATUS, RP0	; Access bank 0
	return 				; return from subroutine	;}				
;===========================================================================================

; Delay for 10 microseconds ;{	; Call = (2 cycles) ========================================
delay_10us	
		movlw 	0x0F  		; Repeat 15 machine cycles	(1 cycle)		
		movwf 	count 		; Store value in counter	(1 cycle)		
		
		decfsz 	count, 1	; Decrement counter 		(2 cycles)				
		goto 	$ -1 		; Continue if not 0 		(2 cycles)
	return 				; End of delay 	 ;}	
;===========================================================================================

; Delay for 100 microseconds ;{	; Call = (2 cycles)  =======================================
delay_100us	
		movlw 	0xA4  		; Repeat 164 machine cycles	(1 cycle)
		movwf 	count 		; Store value in counter	(1 cycle)
		
		decfsz 	count, 1 	; Decrement counter (1 cycle)
		goto 	$ -1 		; Continue if not 0 (2 cycles) 4 + (164 * 3) = 496
		goto 	$ +1		; 497 + 498
		nop			; 499
	return 				; End of delay (1 cycle for 500 cycles total) ;}
;===========================================================================================
 
You need a speed sensor, PID control and output adjusting the speed based on the PID error correction.
Microchip has app notes on PID with a PIC. A hall sensor or tachometer input from the coil can give u the speed data. Then all u need is a throttle body with an E throttle so u can control it with an electrical signal. No diddling with servos or steppers, these things are OTC or available form a junkyard and are quite reliable. This is fuel injected I presume?

I'd suggest a PIC 16f886 as the baseline PIC: built in comparators , T0CK, PWM,RS232 comms for PC monitoring or remote speed changes, EPROM for rembering setup, internal clock of 8MHZ , up to 20MHz with a crystal, lots of I/O for creating an independent HMI for local control, eg LCD panel or touch screen. the 16f886 can also do capacitive touch pads for input , great for grimy/greasy environments.
 
Thanks for the answers and the code . Right now i'm working on some improvments both on the hardwar and software setup and i have yet to decide if i will be using steppre motor or a servo ..

A couple of improvments will be to use dc-dc SSR's instead of the mecanical relays both for the ignition and the starter solenoid (the ignition SSR is ofcause only for petrol engines ;) ) .

I also will use a K type Thermocouple with a MAX6675 coldjunction compensator circuit instead of the LM35 used in the project i have linked to ..
 
You need a speed sensor, PID control and output adjusting the speed based on the PID error correction.
Microchip has app notes on PID with a PIC. A hall sensor or tachometer input from the coil can give u the speed data. Then all u need is a throttle body with an E throttle so u can control it with an electrical signal. No diddling with servos or steppers, these things are OTC or available form a junkyard and are quite reliable. This is fuel injected I presume?

I'd suggest a PIC 16f886 as the baseline PIC: built in comparators , T0CK, PWM,RS232 comms for PC monitoring or remote speed changes, EPROM for rembering setup, internal clock of 8MHZ , up to 20MHz with a crystal, lots of I/O for creating an independent HMI for local control, eg LCD panel or touch screen. the 16f886 can also do capacitive touch pads for input , great for grimy/greasy environments.

I will read trough that app note and hopfully i eventually will figure out the PID thing :) ..

When it comes to the chocie of PIC to use i have some 16f628A and 18F252 in my parts box , i was also thinking about geting hold of a few 40 pin 18F4450 not sure if one of those can be used for this project .. anyway i will look into the 16F886 too ...

Anyway before i make a choice i need to find out what i want to build into the Governor ( like manual speed controll and a few other things i have in mind )

When it comes to the type of engine i just need to see what i can find at the junk yard and what i have to pay for it .. I'm also thinking about running the engine on producer gas from a gassifier and i have to check if i can run fuelinjected engines with out to much modifications ...
 
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I'm also thinking about running the engine on producer gas from a gassifier

Interesting, you are right up my alley. I was seriously considering doing a gasifier project myself.

Well, firstly, I can tell you right off the bat that syngas is NOT very energy dense. Especially if you are feeding the gasifier with just plain air and not pure oxygen. With air (some oxygen diluted with lots of nitrogen) the product has about 1/3th the energy of natural gas. Also, know that gasifiers are notoriously bad at being able to throttle up and down, this is why they work good for generators, where they are expected to operate relativity constantly. With all this in mind, the size of the gasifier you're going to need to run a several dozen horsepower auto engine close to it's peek efficiency/power constantly is going to be prodigious. 55 Gallon drums won't cut it, you will need industrial sized containers (Think small grain silos). It will likely be a very large project, and consume all of the wood/biomass.

But do you really need that much power...?

You should consider that the average 30-80 HP small auto engine will produce 22 to 60 Kilowatts of electrical power! But the average household uses only about 9 Kilowatts, the average person only really uses about 1-3 Kilowatts of power on a casual day-to-day basis, depending on the person of course. If you're welding, using an electric clothes dryer, an electric oven, electric heaters, leaving all your lights on constantly, et cetera, et cetera, then you may use quite a bit more. However, consider that there are alternatives for most of this stuff, and you only use most of those things for limited times anyway. Finally consider that when you sleep, you would normally turn all your appliances off, accept for maybe your water heater and a few odds and ends. In any case, the average single person really only uses 1-3 Kilowatts.

Here's the thing, you can get upwards of 7,456 watts off of just a 10 HP genset engine... a whole lot of electricity for not a lot of engine honestly.

The real problem is not the constant power, it's the peek power usage. With all of the above on at one time things could get up into the tens of Kilowatts range. The best way to deal with this though, is not by making a larger and larger genset, but rather making some kind of energy storage system. You do this because over time, a small genset produces more than enough power for ones needs, but can't make the peek power when required. And a large generator that can handle the peek load, will operate very poorly at the typical load of daily use, and will not be able to respond quickly to a sudden demand for more power.

An energy storage system solves this dilemma. It works because when demand is low, your storage system is charging up over time. But when demand suddenly becomes high, the storage system and your generator will discharge into the load at the same time. A good storage systems can dump significantly more power than your generator can, so long as it's only for short duration's. All in all, this method is effectively tripling, quadrupling, or even farther increasing your systems peek power, with the added benefit of being able to respond immediately when the power is needed.

So you should consider if you really need to go and use a full auto engine.

Alternatives?
Something I was considering is a sterling engine to convert biomass into electricity. So long as you can get all of the heat of the biomass to go through the thing, the sterling engine is really energy efficient at converting heat into electricity. You also have the added benefit of not needing to mess with an alien solid-to-gas conversion apparatus, where the product is a highly toxic and flammable gas. One only needs to build something resembling a wood burning stove to use a sterling engine. Unfortunately, the sterling engine is just as alien, if not more so than a biomass gasifier. And they also have strict tolerances that make precision machining a fair necessity. This makes a sterling engine genset a fairly hard project. If you could find someone that had or had access to a good CNC machine, and took every opportunity to use auto parts where you could, this IMO is a better system for making power than a biomass gasifier.


Err... back on topic now...


Sensing RPM off the coil is a good, proven to work method. It's more or less contact free, contaminant proof, and would most likely directly give you the actual RPM, which makes some other things simpler. The only problem is, if you're not careful, you could end up sending 30~40KV into your PIC. And we really can't know what it will tell your engine to do when that happens. Hopefully "Shut down".

If you use this method, you are obviously going to need to HV harden the coils sensor. But it might also be a good idea to put in a HV hardened watchdog circuit that will kill the engine if the PIC stops sending it a fairly specific signal. This will insure the engine comes to a halt if the defenseless little PIC happens to get zapped. CMOS chips don't like HV at all, and you can't rely on one to come to a safe state when exposed to such things.
 
The gassifier i have in mind is not the 55 gallon drum type .. my idea is to have a two camber setup . one camber is the burn camber witch provides the heat to gassifie the feedstock in the second chamber , where it will be gassified in an oxygen starved inviroment.. This setup wil be able to use any carbon based material as a feedstock ..

When it comes to the power i will be needing i guess a 10KW unit would be enough but i'm looking to be able to grow plants indoors in the wintertiem and depending on the size of the building i will have the ligh alone can use more than 10 kw ..

Since i'm going to use a ssr connectet to the PIC to turn on the ignition i guess the engine will stop if the PIC die since the SSR will loose it's input from the mcu and shut off the engine ..
 
The gassifier i have in mind is not the 55 gallon drum type .. my idea is to have a two camber setup . one camber is the burn camber witch provides the heat to gassifie the feedstock in the second chamber , where it will be gassified in an oxygen starved inviroment.. This setup wil be able to use any carbon based material as a feedstock.

You do understand that a major combustible gas produced by a bio-mass gasifier is actually carbon monoxide, right? And that you will require oxygen to make carbon monoxide gas out of a solid carbon source. You can't simply heat dry carbon in an oxygen starved environment, that won't work. Now doing that with bio-mass, like wood, can distill out volatiles like methanol and toluene. It can also create hydrogen gas through steam reforming if there is enough water present. But your method will not make solid dry carbon into carbon monoxide. You need oxygen to do that.

Yes, I am not pulling your leg. Carbon monoxide gas absolutely is 100% combustible. It's carbon DIOXIDE that is not combustible. If you don't believe me, at the very least, you will still need carbon monoxide to make hydrogen through steam reforming. Finally, carbon monoxide gas also happens to be a cyanide class of poison, which will kill you dead through cellular asphyxiation in fairly small concentrations. So... be careful, and don't try and operate something like this indoors. OK?

***** EDIT *****
When it comes to the power i will be needing i guess a 10KW unit would be enough but i'm looking to be able to grow plants indoors in the wintertiem and depending on the size of the building i will have the ligh alone can use more than 10 kw ..

I assume that you are expecting these Wattage figures for your light because you plan on using several large typical high pressure sodium or Halide grow lamp? If so, you should be aware that these types of lamps dissipate most of their energy as heat, and what they do convert to light is not all centered at the optimal spectrum for plant growth. Though they are mostly on target.

I personally have been watching the very high power/performance LED grow lights that have started to come out recently. For one, LED's can be a more efficient electricity to light conversion method than alternatives, meaning less of your energy is converted to heat. Secondly, they are usually tailored to the exact spectrum of light plants use to grow. So more of the light made is actually absorbed by the plants. Watt per growth rate LED grow lamps are about 2.5 to 3 times more powerful that others. So a 300 Watt LED lamp is pretty much the same as a 1000 Watt HPS lamp, with a fraction of the heat output.

Then again, the LED grow lights can be pricey, but are usually about $1 a watt if your getting a good deal. So the above 300 Watt LED lamp will run you $300~$500. And if as you say, you are intending to grow during the winter, you may actually want to have the extra heat produced by the other less efficient lamps. As I said though, LED lamps do not produce nearly as much heat, so you can not rely on them as heaters.
***** EDIT *****

Since i'm going to use a ssr connectet to the PIC to turn on the ignition i guess the engine will stop if the PIC die since the SSR will loose it's input from the mcu and shut off the engine

Guessing = bad.

(hypothetically) If the PIC gets shocked, it can easily take the pin that powers the SSR, and short it directly to Vcc, which of course would hold the SSR on.

Again, one simply can not know what a CMOS chip is going to do if and when it gets hit with a HV spike. You can only (fairly accurately) approximate it statistically. 99 times out of 100, it's going to just short internally, blow up, then go open circuit. In some situations, 99% chance is perfectly fine. But don't think that 99% is as good as a sure thing, because it can easily do just about anything. It might short a pin to Vcc, might short a pin to ground, might go open, might get stuck in some unimaginably convoluted loop that rapidly toggles a pin. Aside from something absurd like purple monkeys flying out of the thing, if you can imagine it, the PIC could do it after getting hit with HV. One just can't know for sure.

The only thing you can be sure of, is the odds of being able to accidentally reproduce complex "safety signal" become statistically impossible the more complex that signal is. This is why, for a virtually 100% safe design, one wants to use just such a signal fed into a watchdog circuit. Ideally with the watchdog circuit having it's own protection to > 2x of the HV areas voltage.

But I digress, realistically we talking about the kinds of design choices that are really only necessary for very safety critical applications. Airplanes, medical devices, NASA space craft, military weapons systems, nuclear power plants, and so on and so forth. Most of the time, lots of lives are at stake with these things, not just your own.
 
Last edited:
Well this thread has tickled my memory. A couple years ago I designed and built (made a few), add on performance controllers for turbo vehicles based on the 16f886. Used ALL the I/o and then some via double/triple duty.
Anyway It has a robust power supply section with both tranzorb and MOV suppression to meet automotive standard.
https://www.electro-tech-online.com/custompdfs/2013/02/autotransients.pdf

Sensors included Mass air flow, oxygen/AFR, coil - tacho via an optoisolator, Primary MAP - boost control, secondary MAP for dynamic barometric boost control.
The design featured a relatively new electronic blow off valve controller to optimize boost conservation between gearshifts. There are 3 closed (PID) and 3 open loop tables for boost control over all conditions.
There is an 18 item hierarchical menu structure with both pseudo analog and 4 digit 7 segment displays capable of displaying independent data sets.

Anyhow I attach the schematic and board layout and draft user manual.

Note the schematic power supply section and components WILL handle ALL auto transients. It uses a staged transient snubber, a tranzorb for the fast low power transients backed by an MOV of slower 'load dump' handling and the regulator is automotive grade with a 60V input tolerance suitable for 24 Volt jump starting tolerance etc.

There are separate digital /analog power sections to handle ground bounce due to hi current switched inductive loads via the 4 NFET output drives.

FYI there's about 6.6Kb of pure machine code in the programming for all the features.
 

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You do understand that a major combustible gas produced by a bio-mass gasifier is actually carbon monoxide, right? And that you will require oxygen to make carbon monoxide gas out of a solid carbon source. You can't simply heat dry carbon in an oxygen starved environment, that won't work. Now doing that with bio-mass, like wood, can distill out volatiles like methanol and toluene. It can also create hydrogen gas through steam reforming if there is enough water present. But your method will not make solid dry carbon into carbon monoxide. You need oxygen to do that.

Yes, I am not pulling your leg. Carbon monoxide gas absolutely is 100% combustible. It's carbon DIOXIDE that is not combustible. If you don't believe me, at the very least, you will still need carbon monoxide to make hydrogen through steam reforming. Finally, carbon monoxide gas also happens to be a cyanide class of poison, which will kill you dead through cellular asphyxiation in fairly small concentrations. So... be careful, and don't try and operate something like this indoors. OK?

***** EDIT *****


I assume that you are expecting these Wattage figures for your light because you plan on using several large typical high pressure sodium or Halide grow lamp? If so, you should be aware that these types of lamps dissipate most of their energy as heat, and what they do convert to light is not all centered at the optimal spectrum for plant growth. Though they are mostly on target.

I personally have been watching the very high power/performance LED grow lights that have started to come out recently. For one, LED's can be a more efficient electricity to light conversion method than alternatives, meaning less of your energy is converted to heat. Secondly, they are usually tailored to the exact spectrum of light plants use to grow. So more of the light made is actually absorbed by the plants. Watt per growth rate LED grow lamps are about 2.5 to 3 times more powerful that others. So a 300 Watt LED lamp is pretty much the same as a 1000 Watt HPS lamp, with a fraction of the heat output.

Then again, the LED grow lights can be pricey, but are usually about $1 a watt if your getting a good deal. So the above 300 Watt LED lamp will run you $300~$500. And if as you say, you are intending to grow during the winter, you may actually want to have the extra heat produced by the other less efficient lamps. As I said though, LED lamps do not produce nearly as much heat, so you can not rely on them as heaters.
***** EDIT *****



Guessing = bad.

(hypothetically) If the PIC gets shocked, it can easily take the pin that powers the SSR, and short it directly to Vcc, which of course would hold the SSR on.

Again, one simply can not know what a CMOS chip is going to do if and when it gets hit with a HV spike. You can only (fairly accurately) approximate it statistically. 99 times out of 100, it's going to just short internally, blow up, then go open circuit. In some situations, 99% chance is perfectly fine. But don't think that 99% is as good as a sure thing, because it can easily do just about anything. It might short a pin to Vcc, might short a pin to ground, might go open, might get stuck in some unimaginably convoluted loop that rapidly toggles a pin. Aside from something absurd like purple monkeys flying out of the thing, if you can imagine it, the PIC could do it after getting hit with HV. One just can't know for sure.

The only thing you can be sure of, is the odds of being able to accidentally reproduce complex "safety signal" become statistically impossible the more complex that signal is. This is why, for a virtually 100% safe design, one wants to use just such a signal fed into a watchdog circuit. Ideally with the watchdog circuit having it's own protection to > 2x of the HV areas voltage.

But I digress, realistically we talking about the kinds of design choices that are really only necessary for very safety critical applications. Airplanes, medical devices, NASA space craft, military weapons systems, nuclear power plants, and so on and so forth. Most of the time, lots of lives are at stake with these things, not just your own.

One thing is even though we both are talking about gassification we are also talking about two different system .. What you say about oxygen do apply to the one chamber design where the oxygen is mostly used to maintian the heating of the feedstock. My system will use the same amount of air as the Drum based gassifers but i have separated em in to 2 different chambers and the chamber for the feedstock will have a oxygen STARVED enviroment.. no mater what design you are usine to much oxygen ( like to much air) will resulit in a burning feedstock or worse, an explosion ...

When it comes to the energy in the producer gass you are right it's way less than other fules due to the fact that the heavy carbon chains are left in the filter systems as tares , with the system i have in mind it will be collected in a 3 stage system and it can be refined into the same products as regular crude oil .. just heating it up and mix it with the påroducer gas will make a much more potent fule..

Since i Grow my own tobacco i have done reseach when it comes to the use of artificial light and ther are two collor spectrums that is needed Blue and red and no mater what type of light source you use it need to contain the right amount and it also need to change during the plant growth cycle ...

since my governor setup will be used for both gasoline and diesel engines i will go for a magnet picup solution but you are right the cmos could leave the SSR in an on state but there are optocoupler and other solutions to deal with it in case it's needed and i will look into em if i find out i will go for a solution using the coil as a trigger :)
 
Well this thread has tickled my memory. A couple years ago I designed and built (made a few), add on performance controllers for turbo vehicles based on the 16f886. Used ALL the I/o and then some via double/triple duty.
Anyway It has a robust power supply section with both tranzorb and MOV suppression to meet automotive standard.
https://www.electro-tech-online.com/custompdfs/2013/02/autotransients.pdf

Sensors included Mass air flow, oxygen/AFR, coil - tacho via an optoisolator, Primary MAP - boost control, secondary MAP for dynamic barometric boost control.
The design featured a relatively new electronic blow off valve controller to optimize boost conservation between gearshifts. There are 3 closed (PID) and 3 open loop tables for boost control over all conditions.
There is an 18 item hierarchical menu structure with both pseudo analog and 4 digit 7 segment displays capable of displaying independent data sets.

Anyhow I attach the schematic and board layout and draft user manual.

Note the schematic power supply section and components WILL handle ALL auto transients. It uses a staged transient snubber, a tranzorb for the fast low power transients backed by an MOV of slower 'load dump' handling and the regulator is automotive grade with a 60V input tolerance suitable for 24 Volt jump starting tolerance etc.

There are separate digital /analog power sections to handle ground bounce due to hi current switched inductive loads via the 4 NFET output drives.

FYI there's about 6.6Kb of pure machine code in the programming for all the features.
Thanks for the links .. i guess your project are more than i need for a regular speed governor but i wil have a closer look and maybe i find something i can use for my project :)
 
One thing is even though we both are talking about gassification we are also talking about two different system .. What you say about oxygen do apply to the one chamber design where the oxygen is mostly used to maintian the heating of the feedstock. My system will use the same amount of air as the Drum based gassifers but i have separated em in to 2 different chambers and the chamber for the feedstock will have a oxygen STARVED enviroment.. no mater what design you are usine to much oxygen ( like to much air) will resulit in a burning feedstock or worse, an explosion ...

Maybe I'm not getting you, maybe your not getting me. One thing is sure, it is off topic conversation.

I believe there is an alternative energy section of these forums, maybe we could split the conversation and talk about the gasification aspects in there? I do have more to say about it if you're interested. Mostly, I am still fairly convinced you have got the wrong idea of how the process works. I think you believe that you can simply heat the solids and they will melt, or vaporize, and you can burn the resulting gas. This is a common misconception though.


since my governor setup will be used for both gasoline and diesel engines i will go for a magnet picup solution but you are right the cmos could leave the SSR in an on state but there are optocoupler and other solutions to deal with it in case it's needed and i will look into em if i find out i will go for a solution using the coil as a trigger

Yeah, as universal as a coil sensor is, unfortunately it can never work with diesel. The magnetic pickup method is good, but almost always needs to be calibrated. You could also use an optical pickup, but it has little to no advantages over a magnetic unit. More noise immune in theory, but that's not always true. Also they have problems in dusty/dirty environments.

You will probably need to use coax or a differential pair for the sensor wire. There is a lot of noise in an automotive environment, and any wire is going to act like an antenna and pick it up.

Seems like Mosaic could probably tell you all about that.
 
If you take a closer look at what happens inside a gassifier you will find that pyrolysis is the prosess that breaks down the feedstockk into the various fuels and tars , If you google pyrolysis you wil find a page on wikipedia ( **broken link removed** ) witch explain the prosess

"Pyrolysis is a thermochemical decomposition of organic material at elevated temperatures without the participation of oxygen. It involves the simultaneous change of chemical composition and physical phase, and is irreversible"
"Pyrolysis differs from other high-temperature processes like combustion and hydrolysis in that it usually does not involve reactions with oxygen, water, or any other reagents. In practice, it is not possible to achieve a completely oxygen-free atmosphere. Because some oxygen is present in any pyrolysis system, a small amount of oxidation occurs."

if you take a closer look you will find ther are a lot of different types of gasifiers but they have one thing in common they break up carbon based feedstock into various products in an oxygen starved enviroment :) ..

Feel free to start a tread and i will join in when i have the time :)

Back to the topic :

I know ther ar lots of things to take into consideration when i choose the type of sensor so i will do some reserach into what type they use in cars and find the best one for use in my governor setup ..

If i'm lucky the engine i get already have one i can use atleast for som testing :)
 
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