Hi there!
I am building an xono and I finished the power supply's. I made them hardwired. I can't get more out of them than a maximum of between 23,4V and 24,6. And for what I read it has to be +/- 30V. Where do I get the other 6 V. Its a regulated supply with lm317/337. The capacitance is 4 x 15000 uF each supply. I am using a schuro shielded trafo 64VA with 2 x 30V secundair. Should I change the resisting value with a lower pot, say 1K? They are now 5K. thanks allready for the answer. Have a nice weekend, Teake
I am building an xono and I finished the power supply's. I made them hardwired. I can't get more out of them than a maximum of between 23,4V and 24,6. And for what I read it has to be +/- 30V. Where do I get the other 6 V. Its a regulated supply with lm317/337. The capacitance is 4 x 15000 uF each supply. I am using a schuro shielded trafo 64VA with 2 x 30V secundair. Should I change the resisting value with a lower pot, say 1K? They are now 5K. thanks allready for the answer. Have a nice weekend, Teake
Hi Teake,
With the information you've given it's hard to tell. What is you're psu configuration? Is it crc, clc, or something else?
Assuming that you're not drawing excess current somewhere and the voltage off the rectifier is somewhere near +/- 42 V (1,4*30), you're losing a total of 18 V per rail. What is the voltage potential across the 317/337's? What is the voltage of the psu without the xono circuit attached (use a dummyload of something like 2k/3W)
If you could post a schematic with component values and voltage measurements, you might get more answers.
regards,
Joris
With the information you've given it's hard to tell. What is you're psu configuration? Is it crc, clc, or something else?
Assuming that you're not drawing excess current somewhere and the voltage off the rectifier is somewhere near +/- 42 V (1,4*30), you're losing a total of 18 V per rail. What is the voltage potential across the 317/337's? What is the voltage of the psu without the xono circuit attached (use a dummyload of something like 2k/3W)
If you could post a schematic with component values and voltage measurements, you might get more answers.
regards,
Joris
Hi teake,
Ok, the voltage after the rectifier is good. In the schematic you've posted i notice different values for capacitance from what you posted first (4*15mf). Are the values in the schematic the same as actually used? What is the value of the resistors r5/r6 you've actually used?
Could you give a voltage reading from the input of the regulators (317/337) to ground?
regards,
Joris
Ok, the voltage after the rectifier is good. In the schematic you've posted i notice different values for capacitance from what you posted first (4*15mf). Are the values in the schematic the same as actually used? What is the value of the resistors r5/r6 you've actually used?
Could you give a voltage reading from the input of the regulators (317/337) to ground?
regards,
Joris
With R1 of 270 0hms and P1 of 5K you will not get more voltage out of it. Either make R1 smaller, P1 bigger, do both, or put an R in series with P1. The datasheets should give enough information.
Hi Joris! The other parts have all the same value as in the schematic, only the 4 caps changed from 10000uf to 15000uf 80V. grtz Teake.
and Martin, I got some 10k pots laying around, I will give it a try and tell you about it. Teake.
I take from your post that you did not initially calculate the values for R1 & P1 ?? They form a voltage divider which determines the output voltage as multiples of the reference voltage, all very straight forward and easy to understand, so please review the formula in the datasheet again.
Hi teake,
Martin is right, I didn't look good enough. You could try 120R for r1 but 10k for the pots should be fine.
Actually i'd probably have used the same as you just out of habit and never have noticed it. just like now....
regards
joris
Martin is right, I didn't look good enough. You could try 120R for r1 but 10k for the pots should be fine.
Actually i'd probably have used the same as you just out of habit and never have noticed it. just like now....
regards
joris
hi guys!
I got it all ready, i did put a 750r parallel on the 270r and adjusted it with p1, and got the +/- 30, so I can go on further. Thanks guys, fot your support. grtz teake
I got it all ready, i did put a 750r parallel on the 270r and adjusted it with p1, and got the +/- 30, so I can go on further. Thanks guys, fot your support. grtz teake
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