Stopid basic electronics question

[123splat]

A 12v/5A tv, or anything else,could die when supplied with 12V at 6,or more Amps, BUT NOT FROM THE 6, or more Amps. The TV in this example needs 12V at 5A to supply all it's internal functions. If the supply is capable of delivering more than the TV needs, it DOES NOT care, it only uses what it needs to run it's circuit functions.

Think about your car. Most 12V car batteries are capable of supplying 200 to 600 Amps (required to guarantee that they can run the starter motor with other loads turned on), but most OEM car radios use much less than 4 Amps. They don't blow up when you turn them on. Same with the light bulbs.

Actiive componente, like semiconductors (diodes and transistors) need current limiting, but that is provided in the circuit (like Laser diodes, the protection circuit is the DRIVER). Don't worry, you're cool with the beefed up supply.

Remember, a 3.7v Lipo battery may be capable of delivering 8 Amps or more if shorted, but they work just fine to supply a boost dtriver and a LASER diode.

 

[borgqueenx]

A 12v/5A tv, or anything else,could die when supplied with 12V at 6,or more Amps, BUT NOT FROM THE 6, or more Amps. The TV in this example needs 12V at 5A to supply all it's internal functions. If the supply is capable of delivering more than the TV needs, it DOES NOT care, it only uses what it needs to run it's circuit functions.

Think about your car. Most 12V car batteries are capable of supplying 200 to 600 Amps (required to guarantee that they can run the starter motor with other loads turned on), but most OEM car radios use much less than 4 Amps. They don't blow up when you turn them on. Same with the light bulbs.

Actiive componente, like semiconductors (diodes and transistors) need current limiting, but that is provided in the circuit (like Laser diodes, the protection circuit is the DRIVER). Don't worry, you're cool with the beefed up supply.

Remember, a 3.7v Lipo battery may be capable of delivering 8 Amps or more if shorted, but they work just fine to supply a boost dtriver and a LASER diode.

Your first sentence is confusing me. Youre saying it can die, but also it cant die from more amperage?

 

[BShanahan14rulz]

if it dies, it probably has something to do with the quality of teh voltage, i.e. Device A works with Power Block A, which was designed with a tolerance of 5% because Device A needs somewhat stable voltage and can't deal with a lot of extra voltage.

Device B works with Power Block B, which was designed with a tolerance of 30% because Device B isn't as picky as device A.

Power Block A and B might both be 12V 5A, but one might put out 12.5V, while the other may be putting out 15V. Both are within their specifications, but the 15V one wouldn't play nicely with Device A because Device A might not be able to handle the 15V that Device B has no problem with.


Also, the voltage is the voltage differential between the two electrical contacts. the amps is how many amps it can supply at that voltage. I.E. it should be able to supply between 0 and 5A if it says 5A on the label. It's up to the load to decide how much current it needs.

 

[borgqueenx]

if it dies, it probably has something to do with the quality of teh voltage, i.e. Device A works with Power Block A, which was designed with a tolerance of 5% because Device A needs somewhat stable voltage and can't deal with a lot of extra voltage.

Device B works with Power Block B, which was designed with a tolerance of 30% because Device B isn't as picky as device A.

Power Block A and B might both be 12V 5A, but one might put out 12.5V, while the other may be putting out 15V. Both are within their specifications, but the 15V one wouldn't play nicely with Device A because Device A might not be able to handle the 15V that Device B has no problem with.


Also, the voltage is the voltage differential between the two electrical contacts. the amps is how many amps it can supply at that voltage. I.E. it should be able to supply between 0 and 5A if it says 5A on the label. It's up to the load to decide how much current it needs.

ah thanks its perfectly clear now
also thank you 123splat and the rest

 

[DTR]

When I tested the P3 it operated @ less than 1V over the forward voltage of the diode.
Forward Voltage 4.8V
Power supply 5.5V
1.6A steady.

 

[Elektrotechniker]

Dtr,yes but what happens at higher currents?

 

[DTR]

Dtr,yes but what happens at higher currents?

I am assuming the minimum will rise as the forward voltage does with the current. But that was @ 1.6A and I would only suggest running a single @ 1.8A. Also it is not bad to have a little breathing room either. 6V or 7V would still be a good idea.

 

[Cyparagon]

Interesting - thanks for sharing. If you run it at the full 4A, the required voltage will be higher than at 1A due to the sense resistor (at least 0.3V higher). So I suppose that means at least 1V under all operating conditions, and an extra 0.5V for "breathing room." Power supplies can sag a bit and voltage can be dropped in wire leads.