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Help me make a bench top power supplies

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Chuotnha

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control panel circuits

Hi,

I am trying to make a bench top power supply for my workgroup. I would like to have 4 different channels (for 4 members in our group). Each channel has adjustable (+) and (-) voltages outputs, range from 5 to 15 V and limit current can be from 200 mA to 500 mA. How can I do this Ps with 1 channel select button, 2 increase and decrease buttons (or rotary one), and 1 LCD that shows Voltage and Current values. I need some help to get start.

Thanks

Chuot
 

Re: control panel circuits

try EPE dec 2000 issue it is a pic controlled quad supply
 

Re: control panel circuits

I think you should not spend time on "microcontroller" based devices.
All you want is a power supply!!!

So I would buil a device with 1 transformer and 4 indepandent channles based on 723 voltage regulator in configuration with external n-p-n transisor and resistors(potentiometers) to adjust voltage and current. Maybe it is not new IC but it is still one of the best ever made..
On the front panel you will mount 2 LCD voltmeters (from hobby shop): one for display of voltages and one with shunt resistor for display of currenrs. You will also need, I think, 2-way 4 stages switch to select channels, and 8 panel terminals for banana-plugs as 4 independent outputs.

If you agree with this concept and need more details .. just let us know..
 

Re: control panel circuits

Do you think, after transformer, LM317 (see figure) will help?

Regarding the display module, you may consider 'Display ADC' from Microchip, e.g. TC7107A (LED interface) or TC7116A (LCD interface)

To select the desired voltage/current channel to be shown on LED/LCD, you may consider analog multiplexer, for example MPC508 from Texas Instruments.

Multiple-Turn potentiometer can be employed to emulate the increase/decrease button.
 

    C

    Chuotnha

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Re: control panel circuits

Thank you for your very helpful advices.

I'm still don't know how to connect the select channel button to the circuit. Do I need the timer, counter, decoder circuits, to control the multiplexers, since I need to have only 2 increase/decrease buttons (or 2 rotaries) and one select channel button.

Thanks again,

Chuot
 

Re: control panel circuits

I think you should at least look at the EPE mag article because it can be built several ways, here's a pic of some screens on the lcd
 

Re: control panel circuits

Chuotnha said:
I'm still don't know how to connect the select channel button to the circuit. Do I need the timer, counter, decoder circuits, to control the multiplexers, since I need to have only 2 increase/decrease buttons (or 2 rotaries) and one select channel button.
Click to expand...
You have 4 independent ps channels. You wish to monitor the voltage and current of each channel. So, there are 8 readings to be monitored. You can design a 'manually' triggered 3-bit counter ( 2³ = 8 ) to control the multiplexer.

Another option is suggested by IanP. In his case, you do not need analog multiplexer IC. As IanP mentioned, you need a 8-way selectable mechanical switch to select the proper signal to be connected to ADC.

Do you have the option to use microcontroller?

By the way, if you're interested in the idea frm 'bbarney', you may download the article (free) here:

EPE 2000
 

Re: control panel circuits

Hello to you all, and thanks for everything,

I don't have enough point to down load the artical from the magazine, and I think I could try for microcontroler for my circuit, since I want it to be small and look cool to. Can you help me with the microprocessor design.

Thanks,

chuot
 

Re: control panel circuits

i gave you 20 points to download EPE Mag issue DEC 2000 & Jan 2001
you need both issues for the pic supply
good luck
BB
 

control panel circuits

I have uploaded the EPE Dec 2000 Issue to MCU:
**broken link removed**
You need to register before you could download. Registration is FREE.

Filename:
EPEdec2000.1.rar
EPEdec2000.2.rar

Edit:
Jan 2001 issue were also uploaded to MCU already:
EPEjan2001.1.rar
EPEjan2001.2.rar

(Before creating this post, 'bbarney' has not replied or donated points to 'Chuotnha' yet. After submitting this post (took some time to upload the articles to MCU), I found out 'bbarney' has given 20 points to 'Chuotnha'. Probably this post would give other users, who are interested in this project but are not able to download the articles from EDAboard, the opportunity to get them from MCU.)
 

Re: control panel circuits

Thank's nicleo,I should have thought of that idea,anyway Chuotnha you have 2 way's to get it now and you should read all the post's you can find here on digital or microcontrolled power supply's.Check out some of Fragrance's post's as he has built many EPE projects and has uploaded the codes for the chips.
 

Re: control panel circuits

heres a link for another quad supply
**broken link removed**
 

control panel circuits

Hello you all,

Thank you very much for all your support. I have just download the files from "bbarney" since the "mcu" files could not opend. Now, I will read the articles and I still need your support again, and I really appreciate you all.

chuotnha
 

Re: control panel circuits

Hello,

Anyone knows how to control digital pot without using microcontroler. How would I control 8 different pots (8 channels) by using only 2 push button. Can I do this without using microcontroler. And by the way, which is microcontroler develpment kit that you think Ok for this kind of project.

Thanks

Chuotnha
 

Re: control panel circuits

read this
**broken link removed**
 

control panel circuits

Thank you bbarney
 

Re: control panel circuits

Hi Nicleo,

I am feelling a little stupic, since I do not fully understand how did you come up with the LM317 circuit. Can you please tell me how the circuit work step by step, or you can tell what book, magazine... so I can have some idea about that circuit. I did look up datasheets of those devices, but I have not found something like that. Sorry to bother you again.

Chuotnha
 

control panel circuits

Hi Nicleo,

I just foud your LM317 circuit at fairchildsemi datasheets. Thanks

Chuotnha
 

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