GQ Electronics Technical Support Forum Active Users: / Visits Today:
Highest Active Users:
GQ Electronics Technical Support Forum
Home | Profile | Register | Active Topics | Members | Search | FAQ
Username:
 Password:
Save Password
Forgot your Password?

 All Forums
 GQ Electronics Forums
 2.GQ Geiger Muller Counter
 Switchable GM tube idea for GMC-300		  New Topic  Reply to Topic
 Printer Friendly
Author Previous Topic Topic Next Topic  

garyt

8 Posts
Posted - 08/08/2012 :  22:28:58  Show Profile  Reply with Quote
Let's say that the power supply is set for a tube voltage of ~400VDC.
The voltage is set by the high-side resistor R23 and pot R25.
If I found a DPDT switch with 1000VDC isolation, I was considering using one pole of the switch selecting between the internal M4011 tube and an external pancake tube.

I could then add a trimpot (as a variable R) to the GND side of R25 that is just large enough to get to 950VDC and use the second pole of the switch to short across the ground side trimpot when in internal mode. This would keep the power supply from doing anything wierd while switching.

Obviously, we're talking about voiding warranties here, but any thoughts?
Edited by - garyt on 08/08/2012 22:29:40
Reply #1

ZLM

1261 Posts
Posted - 08/10/2012 :  20:37:20  Show Profile  Reply with Quote
It is a good idea to switch between two tubes. I am still thinking to have a better way to switch, other than switching on a high voltage.
Go to Top of Page
Reply #2

garyt

8 Posts
Posted - 08/12/2012 :  00:29:41  Show Profile  Reply with Quote
I haven't come up with a better way yet. It's also pretty tight inside the box for having the M4011 and a switch AND a connector for the external probe.

By the way, I like your design a lot - it's very elegant and uses all top-notch parts!
Go to Top of Page
  Previous Topic Topic Next Topic  
 New Topic  Reply to Topic
 Printer Friendly
Jump To:
GQ Electronics Technical Support Forum © Copyright since 2011 Go To Top Of Page
Generated in 0.08 sec. Snitz's Forums 2000