Test and Measurement Forum

clicking noise?

Post any questions you may have about our current range of oscilloscopes

clicking noise?

Postby evsc » Tue Feb 16, 2010 10:05 pm

i notice a clicking noise (that sounds like an activated relay) when i attached the picoscope (2203) probe to a circuit. The same noise is also heard when you establish a connection to the scope from one of the analysis programs. which seems fine. but in my case the clicking is also heard repetitively when attached to my circuit (circuit voltage and current are well in the scope limitations), so i am wondering if that is a bad sign... ??
evsc
Newbie
 
Posts: 0
Joined: Tue Feb 16, 2010 9:59 pm

Re: clicking noise?

Postby PeterF » Fri Feb 19, 2010 9:38 am

Hi,
The 220x series scopes have relays which switch between the high and low voltage ranges on each channel. When running in PicoLog, the input signal is fed through from one input connector to both channel’s A to D converters in parallel to get twice the bandwidth. Then the other input connector is routed through the same pair of A to D converters and so on in a cycle. At any one time, the unused input connector and pre-amplifier chain is set to the highest voltage (lowest gain) condition to avoid injecting cross-talk onto the live channel. If either channel is set to +/-1V or lower, then the gain relay will cycle continuously. The only way to have two channels in use without the relay noise is to have both set to any voltage greater than +/-1V (+/-2V to +/-20V, they can be different). This is inherent in the hardware design and cannot be changed or fixed in software.
Regards,
PeterF.
PeterF
Zen Master
Zen Master
 
Posts: 435
Joined: Thu Jun 07, 2007 10:53 am
Location: Cambridgeshire

Re: clicking noise?

Postby evsc » Tue Mar 02, 2010 12:34 am

thanks!
evsc
Newbie
 
Posts: 0
Joined: Tue Feb 16, 2010 9:59 pm


Return to USB PC Oscilloscopes

Who is online

Users browsing this forum: No registered users and 1 guest