Two parallel diodes in a circuit

Thread starter Jahnavi
Start date May 18, 2018
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Circuit Diodes Parallel

In summary, the conversation discusses the potential difference across two diodes in parallel and how it affects their conduction. It is determined that, assuming ideal components, the voltage across the diodes will never exceed 0.3V in the conducting direction. It is also mentioned that in circuit theory, there is no instant when there is no current through a circuit, and that components 'enforce' their v-i relationships across their terminals instantaneously. Additionally, there is a question about why we say the potential drop across a diode is 0.3V, and whether we can consider it as a battery with opposite polarity.

May 19, 2018

NTL2009

CWatters said:

A lot comes down to which model of a diode you are using. The problem statement provides very little information so you have to assume a very crude model, almost an ideal diode but with a defined forward voltage.

Agreed. And the earlier discussion of a 'perfect 12V battery' applied to a 'perfect 0.3V Vf diode' isn't a useful real-world model. It's the same as a 'perfect battery' connected to a 'perfect conductor', or the theoretical infinite force applied to an infinite mass. It is undefined. One or the other has to 'give'.

So either we assume enough internal resistance in the battery so that the diode will clamp the battery terminal's voltage to 0.3V w/o burning up, or we assume the battery can maintain 12 V, and the diode burns out, or somehow the diode can survive with 12V forward voltage (I don't think any real diode can - if you extrapolate the I/V curve I think you will soon reach mega-amps!)

<h2>1. What is the purpose of using two parallel diodes in a circuit?</h2><p>The purpose of using two parallel diodes in a circuit is to increase the current carrying capacity of the circuit. When diodes are connected in parallel, they share the current load, allowing for a higher overall current to flow through the circuit.</p><h2>2. How do two parallel diodes affect the voltage in a circuit?</h2><p>Two parallel diodes have no effect on the voltage in a circuit. The voltage across each diode will remain the same as if they were connected individually.</p><h2>3. Can two parallel diodes be used to increase the voltage in a circuit?</h2><p>No, two parallel diodes cannot be used to increase the voltage in a circuit. Diodes are designed to allow current to flow in only one direction, so connecting them in parallel will not increase the overall voltage in the circuit.</p><h2>4. What happens if one of the diodes in a parallel circuit fails?</h2><p>If one of the diodes in a parallel circuit fails, the other diode(s) will continue to function as normal. The failed diode will no longer carry current, but the remaining diode(s) will still share the load.</p><h2>5. Are there any disadvantages to using two parallel diodes in a circuit?</h2><p>One potential disadvantage of using two parallel diodes in a circuit is that they may not share the load equally. This can lead to one diode carrying more current than the other, potentially causing it to fail faster. Additionally, using two diodes instead of one may increase the cost and complexity of the circuit design.</p>

1. What is the purpose of using two parallel diodes in a circuit?

The purpose of using two parallel diodes in a circuit is to increase the current carrying capacity of the circuit. When diodes are connected in parallel, they share the current load, allowing for a higher overall current to flow through the circuit.

2. How do two parallel diodes affect the voltage in a circuit?

Two parallel diodes have no effect on the voltage in a circuit. The voltage across each diode will remain the same as if they were connected individually.

3. Can two parallel diodes be used to increase the voltage in a circuit?

No, two parallel diodes cannot be used to increase the voltage in a circuit. Diodes are designed to allow current to flow in only one direction, so connecting them in parallel will not increase the overall voltage in the circuit.

4. What happens if one of the diodes in a parallel circuit fails?

If one of the diodes in a parallel circuit fails, the other diode(s) will continue to function as normal. The failed diode will no longer carry current, but the remaining diode(s) will still share the load.

5. Are there any disadvantages to using two parallel diodes in a circuit?

One potential disadvantage of using two parallel diodes in a circuit is that they may not share the load equally. This can lead to one diode carrying more current than the other, potentially causing it to fail faster. Additionally, using two diodes instead of one may increase the cost and complexity of the circuit design.