# What is an H-bridge circuit?

## What is an H-bridge circuit?

An H-bridge is an electronic circuit that switches the polarity of a voltage applied to a load. These circuits are often used in robotics and other applications to allow DC motors to run forwards or backwards.

What is a PWM H-bridge?

H-Bridges. PWM is often used in conjunction with an H-Bridge. This configuration is so named because it resembles the letter H, and allows the effective voltage across the load to be doubled since the power supply can be switched across both sides of the load.

Why does Ah bridge have 4 diodes?

Since there are multiple current pathways, there must be four diodes to provide a path for the induced voltage as shown in Figure 5. No matter the direction of the motor or the induced voltage, it always has a safe pathway to go through the power rail.

### How do you make an H-bridge with a relay?

So without wasting more time here goes…

1. Connect a wire from the motor to the common pin of a relay, repeat with other wire and relay.
2. Jump the 2 Normally open(NO) pins of the relays together.
3. Connect the NC pins, and the jumped together coil pins, to Ground (or negative).
4. Connect the NO pins to VCC (or positive).

How do you make an H-bridge with a transistor?

In H-bridge four npn transistors (BC547) are used in the switch mode configuration. The emitter and collector of transistors T1 & T2 and of T3 & T4 are connected. The collector of T1& T3 is connected to VCC and emitter of T2& T4 is connected to ground. The base of T1 & T4 and T2 & T3are connected through resistors.

Why is PWM used?

Pulse width modulation is a great method of controlling the amount of power delivered to a load without dissipating any wasted power. The above circuit can also be used to control the speed of a fan or to dim the brightness of DC lamps or LED’s. If you need to control it, then use Pulse Width Modulation to do it.

## How can a PWM control an H bridge?

By varying the pulsewidth of the PWM signal, the speed of the motor can be controlled. An H-bridge can replace the transistor and add functionality by allowing the direction of the current to be easily changed.

What kind of circuit is a H bridge?

H-Bridge Circuit. H-bridge is the circuit in which voltage can be applied across the load, in either of the direction. These circuits are frequently used in robotics, especially for the DC motor.

How does a H-bridge motor driver work?

Connect the circuit according to the below schematic diagram for H-bridge motor driver. When we move the 10k pot in one direction, the DC motor rotates in one direction and when we move the Pot to opposite direction then the motor also rotate in opposite direction.

### What can A H-bridge be used for?

The most common use of an H-bridge is to drive a DC motor, allowing directional control. There are various H-Bridge designs, and some use discrete components consisting of MOSFETs, while other designs utilize a dedicated Integrated Chip (IC) H-bridge.

How big of a motor does a H bridge DC need?

Direct motor driving with this chip is only possible for motors that draw less than 100 mA (TC4427A), 150 mA (TC4424), or 340 mA (IXDN404) under load.