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Old 04-15-2006, 09:51 PM   #61
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How do you find the foward reisisatance or whatever? to find the resistance, like .7 ohms? and where would you buy these diodes?
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Old 04-17-2006, 04:08 AM   #62
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Quote:
Originally Posted by rcguy2477
The diodes that have been mentioned throughout this thread have a resistance of .7ohms, so if you were to use a .2ohm resistor, your discharge rate would be reduced to approximately 1.3amps.
diodes have a resistance of 0.7ohm?
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Old 05-03-2006, 06:15 PM   #63
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Differnt diodes have different resistance.
A good diode should have a resistance that reaches close to zero, otherwise it would develope a large voltage drop and it would consume too much power.

There are two resistances in a diode, the FORWARD and the REVERSE RESISTANCE.

The Reverse is allways very HIGH.

If a diode has an forward resistance of 0.7 ohms it would drop a very high voltage across it.

I assume you think that the resistance of a diode is 0.7 ohms because of the cutt off voltage, right? Well, your thoughts are close and it makes sense...but the voltage drop across a diode has nothing to do with its internal resistance. It has to do with the semiconductor material used.
Thee are diodes that have cut off voltages as low as 0.23 volts and as high as several volts. It depends on the construction, type, and materials used.

If th diode had a resistance of 0.7 ohms and you push 30 amps across it it would drop 21 volts across it... that does not happen in a diode.... and it will consume 630 watts.

The resistance that you measure with an ohmeter is NOT ACCURATE. There is a higher resistance across the wires and the probes than the diode...
Ohmeters are used to check if a diode is working and if it is not marked to determine which side is the ANODE and CATHODE.
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Old 05-03-2006, 07:23 PM   #64
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Quote:
Originally Posted by BATT_MAN
Differnt diodes have different resistance.
A good diode should have a resistance that reaches close to zero, otherwise it would develope a large voltage drop and it would consume too much power.

There are two resistances in a diode, the FORWARD and the REVERSE RESISTANCE.

The Reverse is allways very HIGH.

If a diode has an forward resistance of 0.7 ohms it would drop a very high voltage across it.

I assume you think that the resistance of a diode is 0.7 ohms because of the cutt off voltage, right? Well, your thoughts are close and it makes sense...but the voltage drop across a diode has nothing to do with its internal resistance. It has to do with the semiconductor material used.
Thee are diodes that have cut off voltages as low as 0.23 volts and as high as several volts. It depends on the construction, type, and materials used.

If th diode had a resistance of 0.7 ohms and you push 30 amps across it it would drop 21 volts across it... that does not happen in a diode.... and it will consume 630 watts.

The resistance that you measure with an ohmeter is NOT ACCURATE. There is a higher resistance across the wires and the probes than the diode...
Ohmeters are used to check if a diode is working and if it is not marked to determine which side is the ANODE and CATHODE.
does 1N5404 rectifier diode have any resistance?
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Old 05-03-2006, 09:29 PM   #65
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Quote:
Originally Posted by zax
does 1N5404 rectifier diode have any resistance?
zax,

All diodes have a very low forward (bias) resistance and a VERY HIGH reverse resistance.
You do not need to worry about the diodes resistance when making your calculations. It is in the very low milliohms range.

Hope this will help you...
Also, did the answers to your pm's help?

Let me know.
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Old 05-15-2006, 09:37 AM   #66
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Did axxis ever get those cutoff boards for the 030 in stock or is this a dead project?
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