need a "little" help - Electronic Circuits Projects Diagrams Free

deschlayer · 19th April 2008, 02:32 AM

I am trying to make I timed varyable voltage dc power supply. here what it has to do:
1- vary voltage from 1-12 volts dc.
2- allow me to adjust the top end voltage
3- allow me to adjust the bottom end voltage
4-allow me to adjust how long it take to get from say 2volt to 12 volts(like to have a range of 10 seconds to 2 min)

if someone could point me in the right direction as to how to go about leaning how to make this, or has a link to a device simarler to this that would be great. any help is greatly appresiated

kchriste · 19th April 2008, 03:33 AM

Quote:

point me in the right direction as to how to go about leaning how to make this

Look into OpAmp circuits. An integrator, buffer and a pair of OpAmp precision rectifiers will probably do what you want.

deschlayer · 19th April 2008, 04:53 AM

I have been able to read about the opamps, but the buffer and others i cant google, is there a more specific name for the other parts? and just to add I know nothing about electronics exept how to soider, am I in over my head or is this something that I will be able to read enough about to build?

Roff · 19th April 2008, 02:31 PM

There are lots of details you left out, like how much current the load draws, how you are going to trigger the start of the ramp, what happens after it times out, etc.
Why don't you just tell us what you are trying to do?

davidbball13 · 19th April 2008, 02:36 PM

a LM317 might do it ah..... i think

Roff · 19th April 2008, 03:46 PM

Quote:

Originally Posted by davidbball13

a LM317 might do it ah..... i think

That is extremely helpful!

deschlayer · 19th April 2008, 04:00 PM

current is from 0.6 watt to 13.7 watt I want it to contiualy go from the adjustable low point to the adjustable high point, and just loop this in the adjustable time frame, withch I would realy like to have even more range, like from 2 sec to 2 min then up to a couple hours. Idealy I would like it to have two dc outputs that are doin exactly the opisite of each other. to explain what it is: It is a dc powerhead controler to simulate waves in an aquarium.

deschlayer · 19th April 2008, 05:22 PM

here is a link to a retail unit, ther reson I want to build one is that I think they are way too expensive, and I built a 500k volt tesla coil in my garage when I was a kid. so I was hoping is was up to the chalang of build this.

http://www.marinedepot.com/ps_ViewIt...l~vendor~.html

deschlayer · 19th April 2008, 05:34 PM

so If i take a LM317 and put the adjutment resister from 100 to 2k then it will oporate from 1.7 to just under 12 volt. is there a way to make or buy a sweeping resiter that has an adjustable bottom and top range that can be adjusted for sweep time?

deschlayer · 20th April 2008, 06:09 PM

bump^^^^^^^

Roff · 20th April 2008, 06:57 PM

I have backed off from this because it looks like a big project that I don't have enough time to devote to. Perhaps others can help, but anyone who does needs a lot more info:
You gave the current requirements in Watts. Watts is a power measurement. Current is measured in Amps. Can you point to a datasheet of the device(s) that you need to control? "Powerhead" is noninformative.
I'm guessing the current requirements would make this a candidate for pulse width modulation (PWM), but we won't know until we know what sort of device you are controlling (motor, solenoid, etc.).
A microcontroller is probably the ideal part to use as your controller. Do you have experience with them?
If you don't use a microcontroller, it could concievably be controlled with an oscillator, a counter, some logic gates, a D/A converter, and either a PWM circuit or a linear driver, again depending on the load.
You need to post detailed ideas on how you want the control voltage vs time to look.
God knows what other questions will come up.

deschlayer · 20th April 2008, 11:01 PM

I cant get a data sheet, where as I cant find one. the current is 310 milliampere. a powerhead is an under water pump that does not "pump" water just simply moves it at a certain flow rate eg 400gph. it is basicaly an imperler that is housed in a cage with no direct flow just a direction of flow.
it is a motor. as far as voltage vs time. I want it to surge from one voltage to the other and then back again repeting, with all three point being adjustable. eg. "2" volt, to "12" volt, over "30" seconds.
as far as everyones help, I am very greatfull, and has provided me with alot of reading witch I beleiv is pushing me in the right direction

I think another name of what I am looking to build would be a Voltage sweep generator

on1aag · 20th April 2008, 11:10 PM

Hi Deschlayer,

Why do you want waves in your bath-tub ?

on1aag.

blueroomelectronics · 20th April 2008, 11:13 PM

Quote:

Originally Posted by on1aag

Hi Deschlayer,

Why do you want waves in your bath-tub ?

on1aag.

Roff · 20th April 2008, 11:21 PM

The drawing below has 4 variables, not 3. Are you implying that one of the time values doesn't need to be variable?

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19th April 2008, 02:32 AM	(permalink)
deschlayer	need a "little" help I am trying to make I timed varyable voltage dc power supply. here what it has to do: 1- vary voltage from 1-12 volts dc. 2- allow me to adjust the top end voltage 3- allow me to adjust the bottom end voltage 4-allow me to adjust how long it take to get from say 2volt to 12 volts(like to have a range of 10 seconds to 2 min) if someone could point me in the right direction as to how to go about leaning how to make this, or has a link to a device simarler to this that would be great. any help is greatly appresiated

19th April 2008, 04:53 AM	(permalink)
deschlayer	I have been able to read about the opamps, but the buffer and others i cant google, is there a more specific name for the other parts? and just to add I know nothing about electronics exept how to soider, am I in over my head or is this something that I will be able to read enough about to build?

19th April 2008, 02:31 PM	(permalink)
Roff	There are lots of details you left out, like how much current the load draws, how you are going to trigger the start of the ramp, what happens after it times out, etc. Why don't you just tell us what you are trying to do? __________________ Ron

19th April 2008, 02:36 PM	(permalink)
davidbball13	a LM317 might do it ah..... i think

19th April 2008, 04:00 PM	(permalink)
deschlayer	current is from 0.6 watt to 13.7 watt I want it to contiualy go from the adjustable low point to the adjustable high point, and just loop this in the adjustable time frame, withch I would realy like to have even more range, like from 2 sec to 2 min then up to a couple hours. Idealy I would like it to have two dc outputs that are doin exactly the opisite of each other. to explain what it is: It is a dc powerhead controler to simulate waves in an aquarium.

19th April 2008, 05:22 PM	(permalink)
deschlayer	here is a link to a retail unit, ther reson I want to build one is that I think they are way too expensive, and I built a 500k volt tesla coil in my garage when I was a kid. so I was hoping is was up to the chalang of build this. http://www.marinedepot.com/ps_ViewIt...l~vendor~.html

19th April 2008, 05:34 PM	(permalink)
deschlayer	so If i take a LM317 and put the adjutment resister from 100 to 2k then it will oporate from 1.7 to just under 12 volt. is there a way to make or buy a sweeping resiter that has an adjustable bottom and top range that can be adjusted for sweep time?

20th April 2008, 06:09 PM	(permalink)
deschlayer	bump bump^^^^^^^

20th April 2008, 06:57 PM	(permalink)
Roff	I have backed off from this because it looks like a big project that I don't have enough time to devote to. Perhaps others can help, but anyone who does needs a lot more info: You gave the current requirements in Watts. Watts is a power measurement. Current is measured in Amps. Can you point to a datasheet of the device(s) that you need to control? "Powerhead" is noninformative. I'm guessing the current requirements would make this a candidate for pulse width modulation (PWM), but we won't know until we know what sort of device you are controlling (motor, solenoid, etc.). A microcontroller is probably the ideal part to use as your controller. Do you have experience with them? If you don't use a microcontroller, it could concievably be controlled with an oscillator, a counter, some logic gates, a D/A converter, and either a PWM circuit or a linear driver, again depending on the load. You need to post detailed ideas on how you want the control voltage vs time to look. God knows what other questions will come up. __________________ Ron

20th April 2008, 11:01 PM	(permalink)
deschlayer	I cant get a data sheet, where as I cant find one. the current is 310 milliampere. a powerhead is an under water pump that does not "pump" water just simply moves it at a certain flow rate eg 400gph. it is basicaly an imperler that is housed in a cage with no direct flow just a direction of flow. it is a motor. as far as voltage vs time. I want it to surge from one voltage to the other and then back again repeting, with all three point being adjustable. eg. "2" volt, to "12" volt, over "30" seconds. as far as everyones help, I am very greatfull, and has provided me with alot of reading witch I beleiv is pushing me in the right direction I think another name of what I am looking to build would be a Voltage sweep generator Last edited by deschlayer; 20th April 2008 at 11:09 PM.

20th April 2008, 11:10 PM	(permalink)
on1aag	Hi Deschlayer, Why do you want waves in your bath-tub ? on1aag.