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Old 11th Jan 2010, 11:07 pm   #58
ppppenguin
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Default Re: Homebrew Valve Tester

Quote:
Originally Posted by Richard View Post
Re the LT, for the people wanting a range, could this not be DC and variable using a LM317 or similar type device, say 0 - 40v with an additional 40v supply you can connect in series, monitored by another cheap meter unit?....
This is going to need some hefty heatsinking to cover that voltage range at a high enough current to do some heaters. For example a 6080 with a 6.3V 2.5A heater would disspate over 80W in the regulator. I know this is an extreme example but it shows the potential problems. This is why multitap transformers are often seen as the best method. The alternative might be a switchmode regulator or pre-regulator.
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