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lm317t power supply problem

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mart_1986

New Member
the problem

we put the circuit together but when we put my iron moving voltage meter on the board it worked great but when the voltage hit 7volts it made the circuit jump to 15volt

this is very confussing to my cousion as im a newbie at electronics

what do you think
 
Last edited:

crutschow

Well-Known Member
Most Helpful Member
Have no idea what you are asking.

Post a diagram of your circuit.
 

mart_1986

New Member
Have no idea what you are asking.

Post a diagram of your circuit.

sorry should of explaned better

the circuit works great with digital and analogue meter reader but when we put my panel mounted iron moving voltage meter on to the circuit and get it to 7volts it makes the whole circuit to jump to 15volts

9136-PSBench.jpg
 

audioguru

Well-Known Member
Most Helpful Member
Where did you connect your meter?

R1 for an LM317 is supposed to be 120 ohms or less. It can be up to 240 ohms for the more expensive LM117. With 220 ohms on an LM317 then the output voltage might rise without a load.
 

mart_1986

New Member
Where did you connect your meter?

R1 for an LM317 is supposed to be 120 ohms or less. It can be up to 240 ohms for the more expensive LM117. With 220 ohms on an LM317 then the output voltage might rise without a load.

we have flowed the plan so its has the 220ohm at r1 we place the meter at the end of the circuit just before where the exit wires will be to the banana plugs
 

audioguru

Well-Known Member
Most Helpful Member
we have flowed the plan
Please talk in English. Maybe you followed (copied) the plan?

But the plan is wrong.

I do not know why the output voltage doubled when you connected your meter to the output. Maybe your meter was not set to show DC volts and instead was showing DC Amps?
 

mart_1986

New Member
Please talk in English. Maybe you followed (copied) the plan?

But the plan is wrong.

I do not know why the output voltage doubled when you connected your meter to the output. Maybe your meter was not set to show DC volts and instead was showing DC Amps?

sorry for the spelling mate my heads is everywhere my girlfriends waters broke today so im trying to take my mind of it lol yes we followed that plan

0v to 15v
meter info
Polarised Moving Iron Current and Voltage Meters


•Polarised moving-iron meters with robust movements for use on dc and rectified ac only
Accuracy ±8% for battery charger applications
Operating temperature range –20 to +40°C
Snap-in panel fixing
Connections 25mm, 1//4 inch spade terminals
 
Last edited:

audioguru

Well-Known Member
Most Helpful Member
Congratulations, daddy-oh!

R1 should be 120 ohms or less for an LM317 or use a more expensive LM117 instead with the 220 ohm resistor.
 
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