Sage-Tips

How do you protect a voltage regulator?

If the output voltage of the regulator is more than 7 V higher than the input voltage, the emitter-base junction of the internal power transistor can break down and cause the transistor to fail. You can use a shunt diode to prevent this condition (see Figure 2).

What are the terminals on a voltage regulator?

As the name suggests, three terminal voltage regulators have three terminals namely input which is unregulated (Vin), regulated output (Vo) and common or a ground terminal. These regulators do not require any feedback connections.

Why do regulators need to be protected?

The input voltage must thus be limited to that level in a fault situation in which the output is shorted. This circuit shows a way to allow such regulators to be used in situations with higher input voltages.

How is over voltage protection done?

Most power supplies use an over-voltage protection circuit to prevent damage to the electronic components. The protection involves setting a threshold voltage above which the control circuit shuts down the supply or diverts the extra voltage to other parts of the circuit such as capacitor.

Does a voltage regulator protect against surges?

Which Should You Use? Surge protectors protect your appliances and electrical system against transient overvoltage. Meanwhile, automatic voltage regulators (AVR) prevent the damage of your electronic devices against frequent electricity fluctuation or the sudden rise and fall of voltage.

What does a 5V regulator do?

Voltage regulators work most efficiently when a clean DC signal is fed into it, and these bypass capacitor helps to reduce any AC ripple. The regulator in this circuit is a TS7805CZ (5V 1A) regulator, which then steps the 12V voltage signal down to 5V, and pushes this on the output.

How should the voltage regulator be wired to work properly?

The voltage regulator should always be fed as smooth of a DC signal as possible (which gives the best regulated output) so it can regulate it down to its specified voltage. Remember, the input voltage has to be larger than the voltage that the regulator regulates out.

Which type of regulator is considered most efficient?

Which type of regulator is considered more efficient? Explanation: The switching element dissipates negligible power in either on or off state. Therefore, the switching regulator is more efficient than the linear regulators.

Can a switch mode regulator fail in low voltage conditions?

Fortunately most switch mode regulators fail in a low voltage condition. However it is often prudent to put in place voltage limiting capabilities in case of over-voltage conditions. Often this can be achieved by sensing the over-voltage condition and shutting down the converter. This is particularly applicable in the case of DC-DC converters.

What is line regulation in voltage regulator?

Line Regulation Line regulation: A change in input (line) voltage does not significantly affect the output voltage of a regulator (within certain limits) Line Regulation Line regulation can be defined as the percentage change in the output voltage for a given change in the input voltage.

What is over-voltage protection and how does it work?

Voltage clamping: Another very simple form of over-voltage protection uses an approach called voltage clamping. In its simplest form it can be provided by using a Zener diode placed across the output of the regulated power supply.

What are the output voltages available with a fixed regulator?

The output voltages available with fixed regulators covers a large range from 3.3V to 24V with nice values like 5V, 6V, 9V, 15V and 18V available. This series of regulators are excellent for most purposes, they can handle up to almost 30V on the input and depending on the package, up to 1A output current.