12V vs. 9V Adaptor

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SCPD

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Is ther a problem using an adaptor that is 9 volts on a scanner which is said to be 12 volts? I hooked it up and it seems to work fine with no over heating.


The mA ratings on both adaptors are the same.
 
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John_M

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You should use a 12v power source if it is intended for 12v. You may be pushing the 9v power source to it's limits. You can check this by measuring the current draw with a multimeter.
 

JnglMassiv

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It depends on the device. I've found most work better going a little higher than a little lower, that is you might get away with using a 12v source on a 9v device. Of course, do so at your own risk and your mileage may vary. For a scanner, my guess would be that it would turn on and operate but probably would not properly charge the batteries (if applicable).
 

SCPD

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Thanks for the info on this. I might do better to just go and buy an adaptor that is right for the scanner. I would hate to toast this one.
 

John_M

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JnglMassiv Wrote:

It depends on the device. I've found most work better going a little higher than a little lower, that is you might get away with using a 12v source on a 9v device. Of course, do so at your own risk and your mileage may vary. For a scanner, my guess would be that it would turn on and operate but probably would not properly charge the batteries (if applicable).

Why risk damaging (internal scanner power supply components)? No need to take a risk. Just use the power supply for which the scanner was intended to use.
 

JnglMassiv

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John_M said:
Why risk damaging (internal scanner power supply components)? No need to take a risk. Just use the power supply for which the scanner was intended to use.
Because it often doesn't matter. Many low power devices like scanners and radios are regulated soon after the power comes into the device. Furthermore, those AC adapters aren't typically precision calibrated, either. It says 9v but you may get 11.5, even under load.

Obviously don't try it if you're not into experimentation and/or understand how things work.
 

John_M

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JnglMassiv Wrote:

Because it often doesn't matter. Many low power devices like scanners and radios are regulated soon after the power comes into the device. Furthermore, those AC adapters aren't typically precision calibrated, either. It says 9v but you may get 11.5, even under load.

Obviously don't try it if you're not into experimentation and/or understand how things work.

Unless you have the schematic and are familiar with the internal scanner power supply components (Understand how things work). It is a risk especially if you use a power supply rated higher than what the device was intended. All devices don't use the same internal power supply schemes. In short, use a good quality regulated power supply that matches the intended input voltage and with plenty of amperage to operate the device.
 
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Al42

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John_M said:
In short, use a good quality regulated power supply that matches the intended input voltage and with plenty of amperage to operate the device.
If the design really required a regulated supply, the manufacturer would provide a regulated supply. Neither Uniden nor GRE do (unless Uniden's new supplies are regulated).
 

John_M

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RS doesn't even supply power supplies. My 396t's are regulated and my Pro-96 power supply is regulated. I just checked my BC100XLT and it is regulated also. Why risk it?
 
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Napalm

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Putting 9v into something that's rated for 12v *probably* isn't going to damage the scanner. Putting 15 volts into something that's designed for 9, probably will.

If you have the current rating on the 9v supply, go for it.. but nothing beats using the correct PSU for the device in question.
 

kb2vxa

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Hi Napalm and all,

"Putting 9v into something that's rated for 12v *probably* isn't going to damage the scanner."

It won't damage the scanner, no "probably" about it. Trouble is the performance will be degraded, particularly programming and memory which require a stable power source and 9V is at the very lower limit. There are internal voltage regulators to consider and the input must always be higher than thier output for them to function.

"Putting 15 volts into something that's designed for 9, probably will."

With a 9V device I would expect smoke signals saying goodbye. With 12V it's no again, but that's the upper limit and you really don't want to push your luck. A scanner is intended for mobile operation and such equipment is designed to operate in the 10-15 volt range with 13.8 being nominal. This is because an automotive electrical system operates this way. 12.6V being a fully charged battery's terminal voltage with the engine off and the regulator typically charges it at around 14 volts.

The bottom line is always use the proper supply for the job or you're asking for trouble one way or the other. You can always go for overkill in the current department, the more amps the merrier but watch the voltage. You don't want to end up like that traveling gnome that plugged the American appliance into the European outlet.

Now somebody mentioned magic smoke. It's only good when it's of the herbal variety, (the police may have other ideas) but when it's from electrical components it's bad, very bad. Smoke is put in at the factory because it's essential for operation but unfortunately you can't get it back in and no replacement smoke is available. When the magic smoke escapes it's all over Jack, game over.
 
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