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Old 30th Jan 2013, 9:50 pm   #5
WME_bill
Octode
 
Join Date: Oct 2007
Location: Exeter, Devon, UK.
Posts: 1,553
Default Re: Levell TM14 Modern Equivalent?

Levell TM14 insulation tester. The difficulty you will have is that I know of no other tester where you can vary the voltage down to 2.5V.
So I was wondering if you had the manual, and as you apparently haven't, I have scanned my copy and attach it herewith. I do not have the component lists, though most are marked.
Nor the semiconductors, so would be very grateful if you could perhaps let me have a note of the transistors/ diodes when you have opened your unit up.
As to what the fault may be, As all the test voltages suggests the transformer or voltage multiplier rectifier chain. I have a Comark Insulation tester (of 1971 and 1981), which is switchable 25v to 1000V. The transformer failed. The original was specified as a Radiospares economy output transformer, operating 12V to 280v x4 for 1kv. So I used a transistor radio output transformer taken of an old radio, and it has served very well.
Your TM14 only has to generate 120V and multiplies it up, so a replacement should be straightforward, if you are prepared to experiment with several strays. wme_bill m0wpn
Attached Files
File Type: pdf Levell TM14-wm.pdf (906.0 KB, 484 views)
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