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Schematic help
- Thread starter jlawson435
- Start date
What kind of problem are you having with it?
These power supplies only have a transformer, diode bridge (first device after the transformer), and a filter capacitor, fuse, on/off switch, and indicator light. I got one at a flea market for a buck. Nice little supply for a simple CB.
If it isn't working; check the fuse first.
You must be careful when opening up the box and checking voltages.
Live 110v AC current can kill!
Be sure to unplug the power supply before working on it!!!
Be very careful; or ask a friend who knows to show you how.
Next, make a quick check to see if the capacitor isn't shorted inside (unplug the power supply from the wall).
Unsolder the negative-marked lead on the capacitor and turn the power supply back on and check voltage output - keep your fingers out!
If you see DC voltage out now; then the cap is bad and you should replace it with the same value - about a $1 or less.
It is used to filter out AC hum from your radio!
Next thing to check if the capacitor wasn't at fault - would be the 'diode bridge'.
The diode bridge is marked by 'AC' on two of the posts; that is where the only two wires out of the transformer goes.
On the other side of the transformer is the 110v AC is coming in; just inspect to be sure something has gotten loose.
Check the switch with volt/ohm meter - BE CAREFUL when power is on.
You should see 110-120v AC on this side!
The other two posts on the diode bridge will be the DC output and should be marked on the device as such.
Use a multi-meter and probes to check which side is "+" and which one is "-".
Be very careful when the power is 'on' and the box is open.
Make sure that the "+" goes to the "+" terminal on the back.
A diode brige rated at 2-3 amps should cost about $1-2 or so.
NEVER hook up your radio with the voltage reversed; you will pop the protection diode in the radio and will need to replace it.
Or it could have also done other damage already too - if hooked up incorrectly.
The red wire that goes to your Cobra should be on the "+" of the power supply and the black wire to the "-" ONLY.
These power supplies only have a transformer, diode bridge (first device after the transformer), and a filter capacitor, fuse, on/off switch, and indicator light. I got one at a flea market for a buck. Nice little supply for a simple CB.
If it isn't working; check the fuse first.
You must be careful when opening up the box and checking voltages.
Live 110v AC current can kill!
Be sure to unplug the power supply before working on it!!!
Be very careful; or ask a friend who knows to show you how.
Next, make a quick check to see if the capacitor isn't shorted inside (unplug the power supply from the wall).
Unsolder the negative-marked lead on the capacitor and turn the power supply back on and check voltage output - keep your fingers out!
If you see DC voltage out now; then the cap is bad and you should replace it with the same value - about a $1 or less.
It is used to filter out AC hum from your radio!
Next thing to check if the capacitor wasn't at fault - would be the 'diode bridge'.
The diode bridge is marked by 'AC' on two of the posts; that is where the only two wires out of the transformer goes.
On the other side of the transformer is the 110v AC is coming in; just inspect to be sure something has gotten loose.
Check the switch with volt/ohm meter - BE CAREFUL when power is on.
You should see 110-120v AC on this side!
The other two posts on the diode bridge will be the DC output and should be marked on the device as such.
Use a multi-meter and probes to check which side is "+" and which one is "-".
Be very careful when the power is 'on' and the box is open.
Make sure that the "+" goes to the "+" terminal on the back.
A diode brige rated at 2-3 amps should cost about $1-2 or so.
NEVER hook up your radio with the voltage reversed; you will pop the protection diode in the radio and will need to replace it.
Or it could have also done other damage already too - if hooked up incorrectly.
The red wire that goes to your Cobra should be on the "+" of the power supply and the black wire to the "-" ONLY.
I got this from a friend of mine He is out of work and has no money so I am trying to figure out why it is only getting 10 v out I think the transfromer my be out and was going to check with a friend that has a bunch if he has one or what do you think would cause it to only get 10 v out
It's rare for a transformer of this size to fail. They usually have a strong chemical smell when they go bad - something between burnt popcorn and ketone.
Chances are - it's the diode bridge.
If it was the transformer - chances are you would get nothing out of it at all...
Chances are - it's the diode bridge.
If it was the transformer - chances are you would get nothing out of it at all...
all it has is an on/off switch transformer on/ light what I take is the diode bridge and a capacitor with a small resisitor between the + and - at rear before it goes out the back
Use an ohm meter to check the diode bridge with the power supply unplugged. Check between each to points closest to each other - and go all of the way around. Then do the same thing with the two probes in reverse direction. In other words, it should show continuity in one direction and - not the other. A diode bridge has four diodes in them. Each of these diodes allow voltage to flow in just one direction - and not the other. If any two points on the bridge -that are next to each other- show no continuity at all; then the whole bridge must be replaced. Chances are - that is the problem. Also check the voltage coming out of the transformer; it should show about 16-18v AC. That will tell you if the transformer is no good.
If you can take it to your friend's house that has parts - he can probably test the power supply for you too. Better that -than you messing with something that is dangerous to mess with in the first place- if you don't know what you are doing...
If you can take it to your friend's house that has parts - he can probably test the power supply for you too. Better that -than you messing with something that is dangerous to mess with in the first place- if you don't know what you are doing...
one side of the transformer going to the on/off switch showing 119.1 v the other side of the transformer is a white wire and a light blue one it shows 11.25 v
i am show continuity between the post I just noticed it appears the tranformer may have some damage to it where it was wrapped in black it appear ot is damaged and someone retaped it when i removed their tape just a little it appears someone messed with it only on one side.
what i was trying to figure out what transformer i needed there are no mrkings of anytype on this and when i go out to find one i was just trying to figure out which one to get
I think that the friend you have that has components might have one.
Looks like the transformer isn't putting out enough voltage to me...
Looks like the transformer isn't putting out enough voltage to me...