Search found 6 matches

by seanacais
Wed Sep 01, 2010 1:54 pm
Forum: General Discussion
Topic: 5A Constant Voltage/Constant Current Reg (Prt II)
Replies: 12
Views: 2028

Re: 5A Constant Voltage/Constant Current Reg (Prt II)

As i also said though, this mod requires sensing in the ground lead of the load, which means the load can not be connected to the same ground as the input. This is very often no problem at all because the power supply operates off the line with a transformer anyway, so who cares about the input/out...
by seanacais
Wed Sep 01, 2010 1:40 pm
Forum: General Discussion
Topic: 5A Constant Voltage/Constant Current Reg (Prt II)
Replies: 12
Views: 2028

Re: 5A Constant Voltage/Constant Current Reg (Prt II)

Using 1.25v as the reference, if we want to use a 250k pot (and we get adjustment to the full value) we can figure the current as 1/250k because with a 0.2 ohm sense resistor and 5 amps that puts 1v across the 250k pot. With the 1.25v reference we need a resistor 1.25/R=1/250k, or working in k ohms...
by seanacais
Fri Aug 27, 2010 6:57 pm
Forum: General Discussion
Topic: 5A Constant Voltage/Constant Current Reg (Prt II)
Replies: 12
Views: 2028

Re: 5A Constant Voltage/Constant Current Reg (Prt II)

MrAl: I was looking at this with the thought of adding panel meters to the existing circuit to measure set-points and output current. I'm beginning to see that may entail more work than I thought. While I'm interested in seeing the circuit you describe, I do have a slight preference for high side cu...
by seanacais
Fri Aug 27, 2010 5:41 pm
Forum: General Discussion
Topic: 5A Constant Voltage/Constant Current Reg (Prt II)
Replies: 12
Views: 2028

Re: 5A Constant Voltage/Constant Current Reg (Prt II)

I didnt look at this circuit in great detail yet, but i can see that R3 is not in series with the load so there could be some small output current that is not seen by this resistor. Since it is supposed to be a 5 amp regulator, it could be that it was not designed to go down that low. Have you dete...
by seanacais
Fri Aug 27, 2010 5:17 pm
Forum: General Discussion
Topic: 5A Constant Voltage/Constant Current Reg (Prt II)
Replies: 12
Views: 2028

Re: 5A Constant Voltage/Constant Current Reg (Prt II)

you could install the meter between the circuit and the 35 volt input. You will still have minimum current reading of what ever the LM317 circuit is consuming but should be more accurate. I didn't consider that but it certainly bears consideration. My hope was to display the values on a 3-1/2 digit...
by seanacais
Fri Aug 27, 2010 10:07 am
Forum: General Discussion
Topic: 5A Constant Voltage/Constant Current Reg (Prt II)
Replies: 12
Views: 2028

5A Constant Voltage/Constant Current Reg (Prt II)

I was looking at this thread from a few years ago and would like to try to adapt this circuit but two questions came up in my mind. I was hoping someone could explain if I was looking at this the wrong way. The first question concerns R3. Being placed between Vout and the Collector of MJ4502 it is o...