Bridges allow your robot to control high current motors. They literally `bridge` between the low-current logic circuitry of your robot`s brain to the high current demanded from the motors. Many, but not all, use the common `H` arrangement of control circuitry (usually power transistors) to provide on/off and directional controls to the motors - h
Click here to download the full size of the above Circuit.
ence the oft-cited name H-bridge. Though often considered "old school, " motor bridges using relays solve a number of problems, and easily provide for handling motors demanding many amps of current. Especially when purchased surplus, relays offer a cost-effective means to control your robot`s motors. The following two circuits were contributed by robo-maestro Russell Cameron. Circuit 1 is a hybrid solution using a DPDT relay for controlling direction, and a power transistor for on/off control. The transistor can also be driven in low-frequency PWM (pulse width modulation) mode for controlling motor speed. Circuit 2 is a half-bridge using a SPST and SPDT relay and transistor-controlled logic to manage on/off and direction. The bridge requires a split supply (two sets of batteries), and is well-suited for use when driving those small toy motors that are meant for 3V operation. (Like all split-supply drivers, one set of batteries may deplete faster than the other, depending on the driving habits of your `bot. ) A very popular and reasonably priced all-in-one H-bridge motor control IC is the L298. It can control two motors, not just one. It can handle 2 amps per motor, though to get the maximum current be sure to add a heat sink. The L298 has a large cooling flange with a hole in it, making it easy to attach a homebrew metal heat sink to it. If there`s a downside to the L298 it`s that it comes in a special Multiwatt 15 ...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
characters left: