Sony 5 volt 2000 milliamp Power Supply I would also like some one from Paralla

sam_sam_sam

These are switching power supplies

It says 5.00 volts but when you put a volt meter to it it read 5.47 volt even with a load on them

Could·I use these to power a Basic Stamp OEM board with out the on board regulator

I was thing about using a 5 volt zener diode·and powering the Basic Stamp with that will this work

I would also like some one from Parallax to chime in as well

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Sam

Post Edited (sam_sam_sam) : 12/13/2008 1:10:49 AM GMT

PJAllen

There might be a trimpot (adj)·inside, if you can open the case.

Phil Pilgrim (PhiPi)

Forget the zener.

First make sure your voltmeter is reading correctly. With your BASIC Stamp or BOE connected in the usual way to an unregulated Vin supply, measure the voltage on Vdd. Is it 5V? If so, your voltmeter is okay, so try the trimpot. If you can't find one, add a 1N4001 rectifier to the power supply's output. That will drop the voltage by at least 0.6V to a safe level. (It'll be lower than 5V, but still high enough. Be sure to measure it first before connecting a Stamp!)

-Phil

sam_sam_sam

PJ Allen & Phil

Thank you for your help with this

I did open one of them it dose not have a trim pot in it

First make sure your voltmeter is reading correctly. With your BASIC Stamp or BOE connected in the usual way to an unregulated Vin supply, measure the voltage on Vdd. Is it 5V? If so, your voltmeter is okay, so try the trim pot.

I have done this part before and I know that the meter is right but I will make sure of it with another meter

With your BASIC Stamp or BOE connected in the usual way to an unregulated Vin supply, measure the voltage on Vdd. Is it 5V?

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Sam

Leon

5.47 V is probably within spec. for most 5V designs, including the BS2. PICs generally have a recommended Vdd of up to 5.5V.

Leon

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Post Edited (Leon) : 12/12/2008 7:01:34 AM GMT

sam_sam_sam

Leon

Thank you for your reply· that will help a lot

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Sam

LoopyByteloose

The 5.47 is likely high due to no load. If you add a load resistor, it should pleasantly drop.

Since Amps X Volts = Watts and E = I X R, you might estimate what size 1/2 watt resistor won't burn up.

.5 watts = 5.5 volts x amps. A .5 watt resistor can handle at most 1/11 amps [noparse][[/noparse]let's say 1/12 for safety and call it 83 millamps.]

So... R = 5.5 volts/.083 amps = 66 ohms minmun.

But if you use a 1/4 watt resistor it would have to be double or 132ohms minmun.

Anything higher will work safely. Anything lower will get hotter and burn up.

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Leon

Those switching PSs have good regulation, a load resistor won't do much. 5.47 V is probably within the usual manufacturing tolerance for such units.

Leon

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LoopyByteloose

Then, if one is worried about too much volts, inserting one diode will drop the voltage from 0.3 volts to 0.7 depending on the type. Just be sure it can handle 2 amps of current.

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It's sunny and warm here. It is always sunny and warm here.... (unless a typhoon blows through).

Tropically, G. Herzog [noparse][[/noparse] 黃鶴 ] in Taiwan