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Homebrew Equipment A place to show, design and discuss the weird and wonderful electronic creations from the hands of individual members. |
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7th Jan 2011, 1:10 pm | #1 |
Retired Dormant Member
Join Date: Oct 2010
Location: Watlington, Oxfordshire,UK
Posts: 11
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Heater Power supplies
Hi Gents,
I am in the middle of a portable radio project that requires a 7v heater voltage.I have built the battery eliminator and have realised that it is simply a resistor change to enable differerent heater voltages. This I intend to accomplish using some sort of switching. My question, is if I follow this route, what range of heater voltages should I cover? Thanks for your time Alec Last edited by apowell; 7th Jan 2011 at 1:12 pm. Reason: spelling error |
7th Jan 2011, 1:23 pm | #2 |
Dekatron
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,195
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Re: Heater Power supplies
Hi Alec, from memory there appeared to be to be 3 main standards;
2Volts (lead acid accumulators, but also a few at 4v and 6v) 1.4V (most early dry battery portables) 7.5V (a lot of mains/ batt portables where the filaments are in series) Are you using a regulator chip or a resistive dropper? If the dropper, then you will need to vary the resistance for each different set due to the variation in curent draw. Ed |
7th Jan 2011, 1:27 pm | #3 |
Retired Dormant Member
Join Date: Dec 2003
Location: North London, UK.
Posts: 6,168
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Re: Heater Power supplies
Also make sure that the voltage cannot rise unexpected during the switching operation. It wouldn't be funny if you were switching from 1.4V to 2V and the voltage spiked up to 7V while a set was connected.
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