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Measuring current on a voltage regulator without load is just shorting it. Shorting PSUs tends to switch them off. (assuming the regulator isn't shutting down first)
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PC PSU into a Lab PSU
- Thread starter LaZeRz
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Ok I think you've noticed I'm no electronics buff heh but I have a voltage regulater in series with a current regulator the cc coming after the cv but I still get the same thing
EDIT : nevermind I found out I must of wired it wring I will re solder the circuit Tom. I'm tired
EDIT : nevermind I found out I must of wired it wring I will re solder the circuit Tom. I'm tired
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ok finally got my prototype, you could call it of my circuit working
now for my final parts i will be using a lm885 for 5 amps
how do i calculate need W rating of my pots? i blew one today but it was only 3/4 W
but my 3W rheostat also gets hot
now for my final parts i will be using a lm885 for 5 amps
how do i calculate need W rating of my pots? i blew one today but it was only 3/4 W
but my 3W rheostat also gets hot
LaZeRz
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thanks ill see if i can figure it out
LaZeRz
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When used as a rheostat, I'd question their correction factor. If anything, it should be more because the heat is created in a small portion of the device.
For example, what exactly do the manufacturers mean when saying a pot can dissipate 5W? If it were 5W across the whole resistive pad, it would surely be less if the heat were generated using only 10% of the pad.
For example, what exactly do the manufacturers mean when saying a pot can dissipate 5W? If it were 5W across the whole resistive pad, it would surely be less if the heat were generated using only 10% of the pad.
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can you heatsink pots
LaZeRz
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You can heatsink anything, but im not too sure if it will help in this case
regalis
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Lately i found an old PSU in my basement. I soldered a little here and a little there and this is what i got(it isn't finished yet...need some more parts to finish up the built):
The PSU:
The 25W 10 ohm resistor:
OFF:
ON:
The highpower LED from Nichia if i remember right
The wires which are left(2 x normal lines with 5V|GND|GND|12V and one with 3.3V|3.3V and finaly a separate -12V wire):
Any thoughts or suggestions are welcome
The PSU:
The 25W 10 ohm resistor:
OFF:
ON:
The highpower LED from Nichia if i remember right
The wires which are left(2 x normal lines with 5V|GND|GND|12V and one with 3.3V|3.3V and finaly a separate -12V wire):
Any thoughts or suggestions are welcome
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ordering stuff now few pots 338's and resistors tut should be up next week if all goes well
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update order has been shipped should be here monday i will be using a 2 pot adjustment for each voltage and current(in total 4 pots) and max output will be 5A around 11.5 V
LaZeRz
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PSU is finished! Will get some pics and maybe a vid of it charging my boostcap up shortly :
Edit: I ran this thing for 1 hour straight with 0 heat issues The plate resistor stays at around the same temperature as its heatsink and at the end if the run it was ever so slightly warm.
I will post a tutorial soon enough and some pics in 24 hours (hopefully)
Btw benneh, did you get yours working?
Edit: I ran this thing for 1 hour straight with 0 heat issues
The plate resistor stays at around the same temperature as its heatsink and at the end if the run it was ever so slightly warm.I will post a tutorial soon enough and some pics in 24 hours (hopefully)
Btw benneh, did you get yours working?
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PSU is finished! Will get some pics and maybe a vid of it charging my boostcap up shortly :
Edit: I ran this thing for 1 hour straight with 0 heat issues
I will post a tutorial soon enough and some pics in 24 hours (hopefully)
Btw benneh, did you get yours working?
yeah mines working i gave mine the option of CC but havent used it once
i havent ran it for an hour as there is no need but see if you can do that limiting it to say 3v
ill post pics later ....
LaZeRz
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Da PSU...
I got a hacksaw and cut a chunk out of a CPU cooler to make it fit in my box
I got a hacksaw and cut a chunk out of a CPU cooler to make it fit in my box
