1 sec pulse from 30 sec clock

[markelectro]

Torban

Cheers for that.I have taken a look and I will try and re-draw the complete circuit.

When I have worked it all out I will post it and then if you could pull it to bits cos I'm sure I won't get it right first time.

Regards Mark

Torban N all

Still tinkering with 555 timers!!!

Torban can't get a photo transistor circuit to trigger the 555.I will keep playing around in Livewire.


Mark

 

[markelectro]

Hello all

I have been playing around with a 555 circuit.I Was hoping to be able to put the photo transistor trigger to input pin two of the 555 but I can't get it to work,Can someone please point me in the right direction Please???

To show how the circuit runs I have added a switch to activate the sequence.Like Torban says I can calculate the resistors and capacitors to give differant timing to suit my needs.In this circuit I have added Led's to show the state of the pulse red for off and green for on.

Oh!! I added a buzzer where the circuit for the 1sec alternating polarity clock
would go.

Two pics one in the off state( red) and one on (green)

All I need now is to fit in the photo transistor circuit,with your help.

Please advise how to better the circuit.


Kind regards mark

 

[Torben]

Torban N all

Still tinkering with 555 timers!!!

Torban can't get a photo transistor circuit to trigger the 555.I will keep playing around in Livewire.
Mark

Mark,

I found my schematic but it's a mess so I just did up a new one during lunch. Try the one attached below, but replace U1 with your laser and phototransistor--I just used the PC817A because it's essentially the same thing I couldn't find a spice model for the laser/phototransistor. This one will output a 0.517 second pulse every time the beam is broken, so if the beam break detector is across the very bottom of the pendulum swing you should get a half-second pulse once per second. I hope.

Q1 can be a garden-variety switching transistor like 2n3904, 2n2222, etc.


Hope this helps,

Torben

 

[markelectro]

please help with 555 timing

Torban N all

I think I copied the Schema right??? but it does not seem to be working correctly. :-(

I added the Photo transistor to the circuit. When the transistor is receiving the light from the LED. the circuit seems to be OK. When the light is broken as if the pendulum passes between the LED. and the transistor the power is activated as expected as shown in the Led. on the far right (I put this is to show the power is going through) BUT!! it seems that we have no timing sequence from the 555 ???? it just runs until the led activates the transistor again.

I am now at a loss with this, can anyone help????

please see images.


Regards Mark

 

[RODALCO]

The T&N seconds clock on the U tube video is ran from the tachogenerator.

I will make a shot of my 3/4 sekonds Bürks with the pendulum coils in synch, and put that on the other thread.

Hoeraah for digital photo and video technology.

 

[markelectro]

Mark,

I found my schematic but it's a mess so I just did up a new one during lunch. Try the one attached below, but replace U1 with your laser and phototransistor--I just used the PC817A because it's essentially the same thing I couldn't find a spice model for the laser/phototransistor. This one will output a 0.517 second pulse every time the beam is broken, so if the beam break detector is across the very bottom of the pendulum swing you should get a half-second pulse once per second. I hope.

Q1 can be a garden-variety switching transistor like 2n3904, 2n2222, etc.


Hope this helps,

Torben

Torben I'm sorted.

I had to fiddle with the capacitors and resis tors to get it to work as I could not with your schema.

I put another thread in for help and I got this 555 calc prog.It gave me just what I wanted to get your circuit running.

**broken link removed**

If you take a look at the image you will see that the photo transistor is recieveing light but the Led. on far right is still lit this is because I now have a time on period of 3 sec.

I will now be able to adjust to suit my need.

Many thanks for your help on this.

Regards mark

 

[markelectro]

The T&N seconds clock on the U tube video is ran from the tachogenerator.

I will make a shot of my 3/4 sekonds Bürks with the pendulum coils in synch, and put that on the other thread.

Hoeraah for digital photo and video technology.

Ray good news.

I look forwards to that.

Could you give me some more details on how to get the same response from the pendulum with the coil and opamp set up.?


Regards Mark

 

[Pommie]

Can I assume that the pic solution is no longer being considered?

Mike.

 

[markelectro]

Can I assume that the pic solution is no longer being considered?

Mike.

mike

Definitely not!!

The Pic. solution is where I want to be in the end.

I have many thoughts in this area and I am very interested in many aspects of electronics. As a beginner in electronics I am very interested in how parts of a circuit go together to create the final circuit. It does get quite hard for me to understand some of the aspects involved sometimes but this is why I ask the questions and do the googleing for long hours.

The circuits involved in the led, photo transistor and 555 timer I can simulate in Livewire before even starting on the real thing.I use this just to get to see how the parts work,can be very good to learn form.

Your schema and asm. code is very helpful to me and will most probably be the first circuit I put together for this purpose. I will put the results back to the thread when it is complete or when I fall foul.

I thank you again for your efforts and assure you it will be tried out.


Kind regards Mark

 

[markelectro]

Can I assume that the pic solution is no longer being considered?

Mike.

Pommie

Forgot to say why I started the pic tutorial in the first place.

Basically I am a clock geek.I have always wanted to make a free pendulum of my own.I came across a website that makes pendulum drivers, well this set me off-

**broken link removed**
**broken link removed**

I then started to try and gain the knowledge so I could develop one for my self.I put the questions to the forum and could not believe the interest it received-

https://www.electro-tech-online.com/threads/electronically-impulsing-a-pendulum-for-a-clock.28921/

I have very similar interests to people all over the globe.Most if not all of the people interested far exceed my level of electronics but I have been overwhelmed With the kind help I have received form this.I often contact some of the forum member privately but we always put put the thoughts back to share with everyone.

As you can see my goals are quite complex to me and Pic's are the way forward. But Bryan's EM. controller is what I want.

Kind regards Mark

 

[markelectro]

Can I assume that the pic solution is no longer being considered?

Mike.

Hello Mike

Just got back from a long weekend away.I will now start the Pic. project you outlined.

I will put a question to the forum if I get stuck wich I'm sure I will.

First job a parts list.

Will get back!!

Regards Mark

 

[markelectro]

This is what I think you need as far as a circuit goes.
I would suggest a 32768Hz watch crystal as the code for PWM becomes fairly simple.

Anyone got a better suggestion for the input.

BTW, I'm currently playing here while my wife is watching soaps. Looks like it's the same the world over.

Mike.

Mike (pommie) N all

The Parts list-

X1 PIC.16F628A
X1 Quad Half H driver- SN754410
X3 Resistors
X2 Capacitors
X1 Watch Crystal 32768HZ **broken link removed**

Right Hear goes!!

I tend to use -
https://www.maplin.co.uk/?DOY=6m8
for my electronics needs ,this is only due to the fact it is about 10 mins up the road from me.

I have searched their stocks and it seems that they cannot supply most of the items I require.

The Pic. 16F628A- They can supply a 16F628 but without the "A" Again due to my level of knowledge I don't really know how important the "A" is.

The Quad Half H Driver. SN754410-again they sell quad drivers but not this particular model.


The Watch Crystal 32768Hz They do actually sell

Resistors and Capacitors should not be a problem.

My questions are-
Can I use alternative quad drivers that Maplins stock?
Can I use the 16f628 PIC they have?
What value Resistors would I require for the circuit?
What value Capacitors would I require.

Can all these be purchased from one supplier in the uk.I will do a look around on Google!!!

I will first build on Breadboard and then may advance later once this is running.

I may bounce other questions as I look into this so I will apologise in advance for being percistant , like in the other examples we have I have to get to the bottom of this to get it up an running correctly.

I look forward to your replies and any advice you can give.

Kind regards Mark

 

[markelectro]

Mike N all

The Parts list-

X1 PIC.16F628A
X1 Quad Half H driver- SN754410
X3 Resistors
X2 Capacitors
X1 Watch Crystal 32768HZ **broken link removed**

Right Hear goes!!

I tend to use -
https://www.maplin.co.uk/?DOY=6m8
for my electronics needs ,this is only due to the fact it is about 10 mins up the road from me.

I have searched their stocks and it seems that they cannot supply most of the items I require.

The Pic. 16F628A- They can supply a 16F628 but without the "A" Again due to my level of knowledge I don't really know how important the "A" is.

The Quad Half H Driver. SN754410-again they sell quad drivers but not this particular model.


The Watch Crystal 32768Hz They do actually sell

Resistors and Capacitors should not be a problem.

My questions are-
Can I use alternative quad drivers that Maplins stock?
Can I use the 16f628 PIC they have?
What value Resistors would I require for the circuit?
What value Capacitors would I require.

Can all these be purchased from one supplier in the uk.I will do a look around on Google!!!

I will first build on Breadboard and then may advance later once this is running.

I may bounce other questions as I look into this so I will apologise in advance for being percistant , like in the other examples we have I have to get to the bottom of this to get it up an running correctly.

I look forward to your replies and any advice you can give.

Kind regards Mark

Seems that Farnell can supply all the parts But I think they have a min order.
https://uk.farnell.com/jsp/home/homepage.jsp

When I get the resistor and Capacitor values I could order the whole lot from them!!!

Regards mark

Ps. Can a Circuit simulation package that will include Pic be Purchased or is it just too complex? I use livewire but it's not that advanced-

https://www.new-wave-concepts.com/

Regards Mark

 

[eng1]

The Pic. 16F628A- They can supply a 16F628 but without the "A" Again due to my level of knowledge I don't really know how important the "A" is.

The PIC16F628A is a later silicon revision. It uses newer process technologies and there are a few differences with the 628. Their importance really depends on your application. Supply voltage? Power consumption? Program memory size? EEPROM size? Price? (Availability, of course).
Some features/differences are listed in the migration document:
https://ww1.microchip.com/downloads/en/DeviceDoc/40048a.pdf

 

[markelectro]

Hello Mike (pommie) N all

Made an account with Farnells , seemed the logical thing to do!! searched for the required items and they do have what is required.
Before I make a purchase from them could you please take a look to see if all will be ok for use within this project, with the PIC. I don't know if I would be limited to certain aspects of different models/versions available.

Watch crystals-

https://uk.farnell.com/jsp/search/browse.jsp?N=411&Ntk=gensearch_001&Ntt=watch+crystals&Ntx=&_requestid=711553



Quad Half H Driver


https://uk.farnell.com/jsp/search/results.jsp?N=411&Ntk=gensearch_001&Ntt=sn754410&Ntx=


16F628A PIC.-


https://uk.farnell.com/jsp/search/browse.jsp;jsessionid=GF3XEWW5KGVYDQFIAEXZK0Q?N=411&Ntk=gensearch_001&Ntt=16f628a+pic&Ntx=&_requestid=713027



Too much choice can look quite confusing


Regards Mark

 

[Pommie]

Those all look ok. You should also order the parts for a 5V supply.

1 x 78L05
2 x 47uF electrolytic capacitors
4 x 0.1uF capacitors (extra for decoupling)

You may want to swap the 16F628 for a 16F88 as the later has a more flexible internal clock and it should be possible to develop a non crystal version with the 88. By timing the main clock and dividing it down in software, a very accurate 1 second pulse should be possible.

Having now read through the various threads and links, I think I may have misinterpreted what you require.

As I understand it, your clock is powered from 12V DC and outputs a 12V pulse every 30 seconds. Your slave clock requires a 24V AC signal every second.

I assumed that the slave required 24V DC for 0.5 seconds and the reverse voltage for the other 0.5 seconds.

I now think that it requires 24V @ 50Hz for 0.5 seconds and no voltage for the remaining 0.5 seconds.

Either way, the hardware will still work but the software will require some modification.

Mike.

 

[markelectro]

Those all look ok. You should also order the parts for a 5V supply.

1 x 78L05
2 x 47uF electrolytic capacitors
4 x 0.1uF capacitors (extra for decoupling)

You may want to swap the 16F628 for a 16F88 as the later has a more flexible internal clock and it should be possible to develop a non crystal version with the 88. By timing the main clock and dividing it down in software, a very accurate 1 second pulse should be possible..

Mike Many thanks for the reply.

Are you suggesting purchase the 16F88 at this stage or at another time?
The 16F628 is fine by me but as you know I'm really at the mercy of your help on this as I could not do it by myself.I think I will purchase both just in case anyway!!!

Having now read through the various threads and links, I think I may have misinterpreted what you require.

As I understand it, your clock is powered from 12V DC and outputs a 12V pulse every 30 seconds. Your slave clock requires a 24V AC signal every second.

I assumed that the slave required 24V DC for 0.5 seconds and the reverse voltage for the other 0.5 seconds.

I now think that it requires 24V @ 50Hz for 0.5 seconds and no voltage for the remaining 0.5 seconds.

The clock is 12v supply but has fitted a rheostat to bring down the voltage to what ever will run the clock, more slaves more voltage!!

With my 24v 3000hm: AC. slave a changeover relay and 24v supply is usually fitted between the clock and the AC. slave. The relay to change the voltage from DC. to AC. The Slave requires an impulse length of approx 0.7

The two wires coming out of the slave will have -

wire one= +24v wire two= -24v
(and then rotated to)
wire one= -24v wire two= +24v

So both wires coming out of the slave will have-

approx 0.7 sec pulse length of 24v+ and approx 0.7 pulse length of -24v and then reversed next time around.

Either way, the hardware will still work but the software will require some modification.

I will go ahead and purchase the parts and then have a go at the construction. I think it will be a case of experiment and see where it goes.

I will see and if I can dig up some literature on the slave.


Once again your help is very much appreciated. To assure you I will see this project through to the working completion.


Kind regards Mark

 

[markelectro]

Mike

Been reading through some literature on the slave and at the moment I'm a little confused but I will try and explain the opperation of the clock as STD. and then in our project

In a normal working scenario the slave would be powered from a seconds contact set that is positioned in the middle of the pendulums swing (see image) Every time the pendulum passes centre it makes a contact. Each contact is sent to either a relay box or to a relay like in the other image to the back of the dial. The changeover relay will convert the DC. into AC. so the power is reversing on each pass of the contact set. From the relay the power is then sent to the slave (see image) this slave receives the 24v AC. current 1 x every second as the pendulum passes centre 1 x every second. the actual impulse length to this slave wants to be approx 0.7 sec long, any more is wasted so not too important.

Pass one of the pendulum (1st second) see image
see bipolar slave jpg.
Pass 2 of the pendulum (Next second) see image


That is what the slave requires and how it is powered in the normal Gent system.(above)


My project was to do all that but using pic's


In our PIC. project we have no contact set in the clock or changeover relay.

The PIC. and the circuit is required to do all that.

On a 30 sec pulse from the clock going to the PIC. it will short out the processor causing a restart. The circuit would then generate 30 pulses (seconds) for the bipolar 24v 3000hm: slave. On the next 30 sec pulse it would reset and do it again.

I want the pic to be controlled from the Master clocks 30 pulse so it is all still governed by the pendulum, so stop the pendulum and the PIC does not run The cycle.


That's blown my brain now and I hope it's all right.

If you have any qestions please ask.

regards Mark

 

[Pommie]

Mark,

I understand the contact and the changeover relay. The SN754410 does the same job as the changeover relay. What I am unsure of is your description of the voltages. From your description, the mechanism that would normally drive the slave would be powered from 48V DC and the changeover relay would convert it to ±24V - you need 48V in order to get -24 & +24 at the same time. I hope this is wrong and the mechanism is powered from 24V DC and what is actually output is 0V and +24V.

What I had assumed in the circuit diagram is that the 24V AC was the peak to peak voltage and could be derived from the 12V DC of the master. This appears to be wrong and means that the SN754410 will require a 24V supply instead of the 12V. It may be that the slave will work happily on 12V anyway - they probably allowed for long cable runs and consequent voltage drop.

One thing that would be useful would be a wiring diagram of a master/slave combination. Is there one any where on the web that you know of?

I'm also slightly confused about the timing.
You stated,

So both wires coming out of the slave will have-
approx 0.7 sec pulse length of 24v+ and approx 0.7 pulse length of -24v and then reversed next time around.

How can it do this every second?
I had assumed that it would be two 0.5 second periods.
Do you mean, 0.7s pulse of +24, 0.3s of no voltage, 0.7s of -24, 0.3s of no voltage.

Mike.

 

[markelectro]

Mark,

I understand the contact and the changeover relay. The SN754410 does the same job as the changeover relay. What I am unsure of is your description of the voltages. From your description, the mechanism that would normally drive the slave would be powered from 48V DC and the changeover relay would convert it to ±24V - you need 48V in order to get -24 & +24 at the same time. I hope this is wrong and the mechanism is powered from 24V DC and what is actually output is 0V and +24V..

Mike

Yes it is wrong and yes you are right the input to the bipolar slave is 24v but alternating on each wire from 0v and +24v and then +24 and 0v

sorry mike if my description is confusing,this is due to my level of electronicd experiance.

What I had assumed in the circuit diagram is that the 24V AC was the peak to peak voltage and could be derived from the 12V DC of the master. This appears to be wrong and means that the SN754410 will require a 24V supply instead of the 12V. It may be that the slave will work happily on 12V anyway - they probably allowed for long cable runs and consequent voltage drop.

You are right again.Normally the slave would get the 24v from additional sorce usually via the same box that houses the changeover relay.You are right also to sugest that the slave can run from 12v. I tested it at 12v and it works fine.So I'm unsure why exactly it is 24v perhaps you are right in saying that it is for longer wires??

One thing that would be useful would be a wiring diagram of a master/slave combination. Is there one any where on the web that you know of?

I willhave a look at what I have and post them.

I'm also slightly confused about the timing.
You stated,

How can it do this every second?
I had assumed that it would be two 0.5 second periods.
Do you mean, 0.7s pulse of +24, 0.3s of no voltage, 0.7s of -24, 0.3s of no voltage.

MMMM!! This is where I get confused too!! I will get back to you on this just so I'm 100% sure.

I have filled out a Farnel order form for the parts, am I still to do so??

Kind regards Mark