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- Thread starter Claymore
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an old car battery and charger is all you need. The charger on its own might give you problems due to voltage fluctuations, and you might lose any radio presets (depending on make) unless there was a battery to keep them active.
Turn the charger off when not in the shop as it can overcharge if left permanently on.
If you use a battery, make sure the terminals are covered so no metal tools can fall onto them
Turn the charger off when not in the shop as it can overcharge if left permanently on.
If you use a battery, make sure the terminals are covered so no metal tools can fall onto them
Eric The Viking
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[I was typing this while Bob was posting, so there's some overlap...]
You might also use any unwanted PC power supply you have knocking about. Recent ones produce high current at 12V, for powering the motherboard. It needs a bit of soldering, but it's not complicated (basically many more wires than you will need).
Older simple chargers should work fine, but the voltage can go quite high, but again a car radio should be fine with that. Modern chip-ccontrolled ones will try to charge the radio, which isn't helpful. If they don't see the load (the radio) behaving as a lead acid battery they may shut down.
OTOH, if you wire up charger -> battery -> radio, it should be fine, although you _might_ get radio interference from the charger (unlikely, but interference suppression won't be a primary objective of the charger designers!). Car radios usually have suppression built into their internal wiring, so again you might notice nothing.
The only nuisance I can think of is earthing (grounding). Car radios use the electrostatic vector of radio waves: being inside a big steel box means magnetic aerials (as found in traditional transistor radios) don't work.
To get the best reception, you need a good ground connection through from the case of the radio to the aerial base. Fitting car aerials to tin garage roofs works well, as long as you use a co-ax aerial cable through to the aerial socket into the radio, not a bit of string. If you use a PC power supply, you might need to _insulate_ the aerial mounting instead, as the power supply needs its earth, and there should only be one earth point in this context. If you don't insulate it, you might find the RCD trips or you get corrosion on the roof around the aerial mounting.
You might also use any unwanted PC power supply you have knocking about. Recent ones produce high current at 12V, for powering the motherboard. It needs a bit of soldering, but it's not complicated (basically many more wires than you will need).
Older simple chargers should work fine, but the voltage can go quite high, but again a car radio should be fine with that. Modern chip-ccontrolled ones will try to charge the radio, which isn't helpful. If they don't see the load (the radio) behaving as a lead acid battery they may shut down.
OTOH, if you wire up charger -> battery -> radio, it should be fine, although you _might_ get radio interference from the charger (unlikely, but interference suppression won't be a primary objective of the charger designers!). Car radios usually have suppression built into their internal wiring, so again you might notice nothing.
The only nuisance I can think of is earthing (grounding). Car radios use the electrostatic vector of radio waves: being inside a big steel box means magnetic aerials (as found in traditional transistor radios) don't work.
To get the best reception, you need a good ground connection through from the case of the radio to the aerial base. Fitting car aerials to tin garage roofs works well, as long as you use a co-ax aerial cable through to the aerial socket into the radio, not a bit of string. If you use a PC power supply, you might need to _insulate_ the aerial mounting instead, as the power supply needs its earth, and there should only be one earth point in this context. If you don't insulate it, you might find the RCD trips or you get corrosion on the roof around the aerial mounting.
nev
Established Member
Have a google for bench power supply, something like
http://www.maplin.co.uk/p/maplin-36w-sw ... pply-l10br
That should do you fine as long as theres enough wattage to cover the draw from the radio (which the boffins in Maplins will know)
http://www.maplin.co.uk/p/maplin-36w-sw ... pply-l10br
That should do you fine as long as theres enough wattage to cover the draw from the radio (which the boffins in Maplins will know)
novocaine
Established Member
https://www.youtube.com/watch?v=NrQWxc4nv7E
battery charger isn't a good way, as already said if it's a smart charger it will stop charging the battery, if it's a real charger it may (may being the operative word here) overcharge the battery, it will produce hydrogen gas (so you can't seal the battery in a box).
look on the back of the radio for the amps needed, you should be ok with a 10a power brick from amazon (12v 10a) but need to see what it says on the tin so to speak.
you'll have to do some soldering and the such to get it to work or do as in the video and use a screw terminal unit.
battery charger isn't a good way, as already said if it's a smart charger it will stop charging the battery, if it's a real charger it may (may being the operative word here) overcharge the battery, it will produce hydrogen gas (so you can't seal the battery in a box).
look on the back of the radio for the amps needed, you should be ok with a 10a power brick from amazon (12v 10a) but need to see what it says on the tin so to speak.
you'll have to do some soldering and the such to get it to work or do as in the video and use a screw terminal unit.
MrTeroo
Established Member
I don't think I would be comfortable using a bodged up system like that in a tinderbox location like a wood workshop.
Hi Fi seperates are so cheap on eBay these days, what's the point of taking even a slight risk of fire?
Maybe plan ahead your wording for the letter to your insurance people? Good luck with that...
Hi Fi seperates are so cheap on eBay these days, what's the point of taking even a slight risk of fire?
Maybe plan ahead your wording for the letter to your insurance people? Good luck with that...
Eric The Viking
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Like which? You might "bodge" it... I wouldn't.MrTeroo":3lwgeaij said:
The supply that SteveF mentions looks ideal, but it is 34 quid (plus shipping, presumably).
A PC power supply is free if it's not doing anything else...
MrTeroo
Established Member
Eric The Viking":3lp079s4 said:
My comment was based on the information given by the OP
Claymore":3lp079s4 said:
Homers double
Established Member
Back in the day I had a 240 to 12v transformer to power my CB radio,the CB was mainly in the car but I had a set up at home as well, just took the unit out of car and plugged it in in the house. What SteveF recommends is virtually the same as I had
