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Do you understand the series and parallel characteristics of voltage regulators

The problem of two voltage regulator diodes in series and parallel

It is known that the voltage stabilizing values of two voltage stabilizing diodes are 8V and 6V respectively, and the forward conduction voltage is 0.7V for both diodes

Question: What are the voltage conditions of two voltage regulators in series and parallel? The forward conduction voltage of the voltage regulator diode is 0.7V, and the reverse is the voltage regulator value.

series

1. Both diodes are connected in reverse, and the reverse voltage is the regulated value, which is 6 8=14V

2. 6V positive connection, 8V negative connection, positive connection is 0.7V, negative connection is 8V, resulting in 8 0.7=8.7V

3. Similarly, 6V reverse connection, 8V forward connection, 6 0.7=6.7V

4. Both diodes are reversed 0.7 0.7=1.4V

parallel

1. Both diodes are connected in reverse, and if the pilot is turned on with a low voltage of 5, it is 6V

2. One is directly connected and the other is reversed. If the voltage is low and the lead is turned on, it is 0.7V

How to calculate the parallel connection of two voltage regulator diodes

There are four types of parallel circuits for two voltage regulators, and there are only two types of parallel voltages for the two voltage regulators in parallel: 6V and 0.7V, as shown in the following figure:

The problem of two voltage regulator diodes in series and parallel

Type: Two voltage stabilizing diodes are connected in reverse bias, and only the diodes with low voltage stabilizing values are broken down to form a 6V voltage stabilizing value. The other three types of circuits have at least one positive bias voltage regulator, so the positive bias pipeline is connected, resulting in a voltage of 0.7V. If connected in series, it is the sum of two.

The function of reverse series connection

1. Often in high-power amplification circuits, the base b and emitter e of the power transistor are connected in parallel with two opposite diodes, which protect the input current of the emitter junction by diverting it;

2. After two diodes are connected in reverse series, they can provide overvoltage protection for the circuit in parallel. When the circuit is overvoltage, the diodes first break through and short circuit;

Bidirectional overvoltage protection. This bidirectional TVS and bidirectional overvoltage protection circuit is generally used in electronic circuits, in parallel with the protected PN junction, to protect the PN from the harm of reverse overvoltage;

Functions: overvoltage protection, electrostatic protection, Voltage clamp, damping.