How Much Power Can a 20A Diode Dissipate in Normal vs. Abnormal Conditions?

[newbieI&E]

Question requires a definition and typical values during normal/abnormal operation (Power dissipation of 20A Diode with 1V across it)

Have got definition no problems, but am struggling with typical values.

Power dissipated would be in watts, but in order to provide that you would need either circuit current or resistance of diode (of which I have neither)

Note from tutor specifies reference to Current rating, so am tending to think he wants something about the P.I.V rating, but if so, I don't see how to define that in terms of normal/abnormal operation.

If someone could point me in the right direction would be much apprieciated.

Thanks

 

[vk6kro]

The power dissipated in a diode would be the voltage across it times the current flowing in it.

The voltage is a fairly constant 1 volt for a power diode.

Suppose it was conducting 6 amps, then the power would be (1 volt * 6 amps) = 6 watts.

The 20 amp rating is the maximum current the diode can carry with a suitable heatsink. So, you could work out the power if it was conducting 20 amps.

The peak inverse voltage refers to the maximum voltage that can occur across the diode when it is not conducting. So this would not dissipate any power.

 

[Mene]

for reaching out for clarification on this topic. Let's break down the different elements involved in power dissipation for a diode.

First, let's define what power dissipation means in this context. Power dissipation is the process by which energy is released in the form of heat when an electrical current passes through a component, in this case a diode. This heat can affect the performance and lifespan of the diode, so it is important to understand how much power a diode can safely dissipate.

Now, let's address the question about typical values during normal and abnormal operation. In order to calculate the power dissipation of a diode, we need to know the current passing through it and the voltage across it. In this case, we are given a diode with a current rating of 20A and a voltage of 1V across it.

During normal operation, the power dissipation of this diode would be 20 watts (20A x 1V = 20W). This means that the diode is operating within its current and voltage limits and is able to safely dissipate 20 watts of power without overheating.

In abnormal operation, the power dissipation of the diode may exceed 20 watts. For example, if the current passing through the diode increases to 25A, the power dissipation would be 25 watts (25A x 1V = 25W). This could potentially cause the diode to overheat and fail if it is not designed to handle that level of power dissipation.

To address the tutor's request for a reference to current rating, we can also mention the Peak Inverse Voltage (PIV) rating of the diode. This refers to the maximum voltage that can be applied in the reverse direction without causing damage to the diode. In this case, the PIV rating should be equal to or greater than 1V to ensure safe operation.

In summary, the power dissipation of a diode is dependent on the current passing through it and the voltage across it. During normal operation, a 20A diode with 1V across it would dissipate 20 watts of power. However, during abnormal operation, the power dissipation could exceed this value and potentially cause damage to the diode. It is important to consider the current and voltage limits as well as the PIV rating when using a diode in a circuit to ensure safe and reliable operation.