Hi,
I recently built the CGS66 PSU, but I am observing a (to me) strange behaviour when measuring the output voltages.
I calibrated the output to +/- 15V without any load connected. Then, after the PSU had been turned off for a few days, I connected a load consisting of two 1M resistors.
When measuring the voltages again, they started out at around 13.5V and slowly rose to +/-15V over the duration of several minutes, both at the same rate. After a little while at 15-15.1V, the voltage started to drop again and hit 14.5 after a couple of minutes.
I then tried connecting a real circuit and the voltages still showed ~14.5 (but possibly still dropping).
Has anyone experienced anything similar? Any ideas as to what may be wrong? Should I just leave the circuit turned on for a while and THEN try to calibrate it again?
As for the circuit parts: I am using a dual 18V/60VA transformer, Farnell 9530444 (http://no.farnell.com/multicomp/mcta060-18/transformer-60va-2-x-18v/dp/9530444?Ntt=9530444) and 35V 2200uF, 50V 22uF and 35V 10uF caps.
--
cheers,
Joakim
I recently built the CGS66 PSU, but I am observing a (to me) strange behaviour when measuring the output voltages.
I calibrated the output to +/- 15V without any load connected. Then, after the PSU had been turned off for a few days, I connected a load consisting of two 1M resistors.
When measuring the voltages again, they started out at around 13.5V and slowly rose to +/-15V over the duration of several minutes, both at the same rate. After a little while at 15-15.1V, the voltage started to drop again and hit 14.5 after a couple of minutes.
I then tried connecting a real circuit and the voltages still showed ~14.5 (but possibly still dropping).
Has anyone experienced anything similar? Any ideas as to what may be wrong? Should I just leave the circuit turned on for a while and THEN try to calibrate it again?
As for the circuit parts: I am using a dual 18V/60VA transformer, Farnell 9530444 (http://no.farnell.com/multicomp/mcta060-18/transformer-60va-2-x-18v/dp/9530444?Ntt=9530444) and 35V 2200uF, 50V 22uF and 35V 10uF caps.
--
cheers,
Joakim