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adyhansolo
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Posts posted by adyhansolo
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Measure the voltage with a portable voltmeter (not connected to earth).
I measured the voltage with a portable digital multimeter (a good one). Any idea? -
It's very strange for me. Maybe if you see this photos with the measurements you can give me the solution.
The second is with the circuit interrupt (rectifier bridge- R2).
[img width=680 height=341]
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I built this project (last version with MC34071). I tried to run the power supply in this morning. I measured the input voltage before insert the op amps in the sockets. The AC voltage was 30V, but the DC voltage was more than 50V, about 55Vdc.
Hi Audioguru,
I don't find the solution of my problem. I checked all the components again and the voltage still remain 54Vdc( measured at C1 pins). If I disconnect R2 the voltage found is normal, 39Vdc. What is wrong? Please help me. -
The peak voltage is 30V x 1.414= 42.4V and the bridge rectifier reduces it to 41.0V with no load.
Maybe your filter capacitor was charged to a higher voltage. R1 should slowly discharge it.
Thank you Audioguru for your replay. I know the peak voltage should be around 42 Vdc, but I don't understand what is wrong. The filter capacitor is ok, it's discharged by R1. Could be the bridge rectifier defective ? I measured the negative voltage ,too. It was 1.47 Vdc. It's ok or it's too high? -
Hi, I need your help.
I built this project (last version with MC34071). I tried to run the power supply in this morning. I measured the input voltage before insert the op amps in the sockets. The AC voltage was 30V, but the DC voltage was more than 50V, about 55Vdc.
I used two caps 6800uF/63V in parallel. I changed them with one 15000uF, but no modification. I measured with , two different digital multimeters with the same value. What is wrong?
Please help and excuse my english. -
Hi,
Can I use for the 3 single opamp only one quad opamp MC34074 ?
0-30V Stabilized Power Supply
in Projects Q/A
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I appreciate you waste your time with my problem.
I measured with two multimeters, including a new one, with the same result. Why the measurements it's correctly in the second circuit ( without negative voltage)?