Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

power supply problem

Status
Not open for further replies.
P

psatish1264

Member level 1
Joined
Jun 28, 2012
Messages
37
Helped
10
Reputation
20
Reaction score
10
Trophy points
1,288
Location
India
Activity points
1,474
Hi Everyone,

i am using one transistorized power supply(voltage rating- 0 to 30V and current rating- 0 to 1A)
And now, the problem is in the channel 1 section it is getting initially loaded to 1A and am not able to vary it.
Please suggest me what may be the problem.
 

Post circuit it will helpful to identify the problem.
 

Hi tpetar,

Thanks for your reply.
I just checked my connector connection and there is no any short circuit.
Is there any other possibility?
 

Hi satish,
If you have a cicuit post it we can find the solution. If you are using series pass npn transistor disconnect the base from circuit and connect it to emiter with 1k resistor and see. Now the transistor will not conduct. output should not be there check an tell

regards ani
 
Last edited:

Hi tpetar,

i have already checked the transistor it is good.
they used lm723cn regulator and ua741cn opamps(3 No's) in this circuit.

- - - Updated - - -

Hi picgak,

yes there is no output.

- - - Updated - - -

Hi,

I am able to vary it. but it is showing the current of 0.95Amp in maximum that too without any load connected to it.
 

Hi satish,
i want to know when you connected as i told is the meter still showing 0.95A. if it is still showing.95A your meter has gone out of calibration. you can check with a good ammeter by connecting after the emiter in series. Hope this helps if so dont forget to click helped me.
regards ani
 
Hi,

i have attached circuit which i have created by tracing board.

 

Hi satish,
where is your meter?
ani
 

hi,

i have not yet finished complete circuit.
The connector in PS1 is connected to some pot's and from pot's to display.
 

Hi satish,
measure the current as said in post no #8 with another ammeter and post the reading
regards ani
 

Hi tpetar,

I have already sent the circuit in post #10
 

Hi satish,
To proceed further it is important to measure when you connected (as i told in post no #5) is the meter still showing 0.95A. if it is still showing.95A your meter has gone out of calibration. you can check with a good ammeter by connecting after the emiter in series.while the base is connected as i told.waiting for your replay with reading from the good ammeter.
ani
 

If there is no output current but the meter shows maximum current, it may be because the current sensing resistor is open-circuit.
 
Hi godfreyl,
Yea that also may be the reason
 

Hi,

Can you please tell me which is the current sensing resistor.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top