1. Home
  2. Hobby Electronics Basics
  3. AC to DC Transformer

AC to DC Transformer

The best strategy in such a case is to use a variable regulated power supply and turn up the voltage until the device works as it should.

You don't have such a supply, but you can try higher and higher voltages until it works. You already did some testing like this and it is obvious that you need a bigger power supply, probably 12 Volt, but you may need more to get it to work.

Get a bigger 12 DC output supply and try it. One that can handle the current without melting. Hopefully that will solve the problem. It should have the max current written on it, but the weight of the supply is a good indicator too, of the current capacity, you simply need a bigger, heavier 12 volt DC supply.

If the machine still doesn't work you need to try a slightly higher voltage. The device may be made for 15 volt and at 12 volt it just lits up but doesn't work properly.

You do not know if the device needs well regulated voltage or if it can take raw rectified Voltage. If the device is very valuable you might want to consider buying a regulated supply, and maybe with variable voltage too, but that is expensive. Most devices with external power supply are fairly tolerant when it comes to voltage. A few volts too much is no problem. But, on the other hand, your device may be an exception.

--
Roger J.
Reply to
Roger Johansson
Loading thread data ...

I have a car audio device (Jensen Sirius satellite receiver) that I want to use inside. I have an extra antenna so that's no problem. It has an FM modulator allowing me to tune it in on my desktop radio so that's taken care of too.

The problem I have is that I need the correct AC to DC transformer. After testing several with 12 volt outputs, I found one that worked. The others either would not allow the unit to power on or would allow it to power on but it would immediately freeze. The transformer that worked has an output of 12VDC, 500mA. It worked for about half an hour before burning out, leading me to conclude that it isn't rated for this application.

I'm not sure exactly what I need. When it comes to electronics, I'm somewhat ignorant. (For instance, I don't understand why only one of about five 12 volt transformers worked.) To select a transformer that's appropriate, what do I need to look for? I'm thinking the voltage would need to be 12. To keep the transformer from frying, do I need something with a higher amp rating? What's the difference between regulated output, max output, and constant output?

Here are some that I'm looking at but have no idea which one (if any of these) would be best:

formatting link
formatting link
formatting link
?ref=2003
formatting link
formatting link
formatting link
formatting link

Any information is greatly appreciated.

-- Christian

Reply to
CMM

Yes. Try looking on the satellite receiver to see if it mentions a figure.

Regulated means the output voltage is constant regardless of the current ( amps ) taken by the load. This is what you want.

Probably the maximum intermittent rated load.

The long term continuous rating. You need it to be > 500mA it seems.

Graham

Reply to
Pooh Bear

I'm an amateur, but I've been around some car audio equipment and I do not think that a 12 volt supply at 1/2 an amp is enough to drive a car audio system. 12 volts x 0.5 amp only yields 6 watts of power for both the radio/tape/cd circuit and the speakers, right?

No wonder the supply burned up.

Reply to
UFO Joe

In that case, it would be a tuner, instead of a receiver (which is what I had originally called it). It just grabs the satellite signal and then sends it back out through an FM modulator. There is not amp or speakers. But, it does have a large lighted display which probably helps account for the extra power it's pulling.

-- Christian

Reply to
CMM

It doesn't say anything but DC 12V. I'm guessing since it's intended to be plugged into a car's cigarette lighter receptacle, that's why it isn't more specific.

Thanks!

-- Christian

Reply to
CMM

I appreciate the feedback from everyone. With this info, I'm sure I'll find what I'm looking for and be up and running soon.

Thanks!

-- Christian

Reply to
CMM

Well... he said it was a receiver not a 'system' but it's unclear what that means. In UK parlance a receiver means just that - no amplifier - US usage includes an audio amplifier.

Graham

Reply to
Pooh Bear

Actually, it is called a tuner if it has no power amp in the US. Its a receiver if it has a power amp, so you use a tuner & power amp, or a receiver. Some marketing types don't seem to understand this. They think that a headphone jack on a tuner makes it a receiver.

--
Service to my country? Been there, Done that, and I\'ve got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida
Reply to
Michael A. Terrell

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.