Power Trip when probing Oscilloscope..

[jrd78ep]

Hello Guys....just wondering why the power is tripping when i probe osciloscope to measure clock signal output from PWM IC (uc3525)...Thanks in advance.

 

[Rleo6965]

Oscilloscope test probe were high impedance and should not affect or loading the output of uc3525. What kind of oscilloscope your using?
I use old model oscilloscope and I removed the Ground pin of AC plug so Oscilloscope Gnd connection will be floating. This to avoid loading or disturb the sensitive PWM circuits.

 

[jrd78ep]

Tektronix tds2012...let say i don't want to remove the ground..and as per my friend advise use the 1:1 transformer between measurement....do you think it'll work? tHanks a lot.

 

[Rleo6965]

Tektronix tds2012...let say i don't want to remove the ground..and as per my friend advise use the 1:1 transformer between measurement....do you think it'll work? tHanks a lot.

Isolation transformer? That's very good advice. Buy one for your safe trouble shooting AC source devices or pwm device and your test equipment.

Wish I can replace my 15 year old Leader 1021 Oscilloscope with Tektronix TDS2012.

 

[sheldonstv]

ok you obviously want to release the magic smoke and loud bangs-what is the item you are trying to repair.....if it is a smps related item you must use an isolation transformer