Re: 1502 TDR Battery problems


Jeff Kruth
 

Hello Folks!

Went to use my 1502 TDR, wouldnt light up. I had built a battery cable for a 12 Volt lead acid external battery, so I charged the 12 V battery up and got it working. I remembered the Battery Fooler mod and looked it up on the Tek site here: 2200 uF cap paralleled with 200 ohm 10 watt resistor. I built one of these in a kaput battery back, plugged it in, and it doesnt work! The little meter is pegged in the green, looks kinda normal.  Yes, I got the capacitor polarity right.  SO I plugged a power supply into the unit: 12V @ 275 mA or so and the unit operated fine. At 13.5 VDC about 200 mA or so.Am I missing something? The Battery Fooler seemed like a good thing.  Should I thinker the cap value? Why the 200 ohm resistor- is this needed to keep the SCR thingy working right? Should the value be increased?Any insight would be appreciated. TIANew info: Tried several caps and resistor values around ther original stated ones: No joy!Regards,Jeff Kruth
BTW Brooke Clarke's 1502 webpage is quite good.

Join TekScopes@groups.io to automatically receive all group messages.