Basic circuit of using L293 formsan H-Bridge Driver is shown in Figure 1. As shown for such inductive loadas DC motor, external diodes for suppressing back EMF must be connected. The MiniBoard uses L293D instead, the L293D has internal diodes, howeverproviding a bit less driving capacity, i. e. , 600mA @4. 5V-36V. From thetruth table, we see that dire
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ction of the motor can control by pin C andD. VINH enable/disable power to the motor, thus for speed regulation, wethen use this pin for PWM signaling. See details, L293. pdf data sheet. A circuit connecting C-52 P1 to L293 driver chip is shown in Figure2. As shown Enable pin 1 connected to P1. 0 is for PWM signaling. We useadditional inverter at pin7 and pin 15 to provide proper logic for easydirectional control. Please note that pin 4, 5, 12, 13 are tied to groundand if heat sinking needed, one method is to make a large area of PCB orsoldering it with a metal sheet, say. Figure 2: Connecting C-52 EVB P1. 4-P1. 7 to L293. External diodes must be connected for L293(not shown in circuit diagram). My latest design put additional inverter forPWM signal at pin 1 and pin 9 to prevent full power delivering to DC motorswhen resetting the 89C52(i. e. , all bits of P1 is logic high). Check thelogic of PWM pins for another microcontrollers. Since there`s no ADC for 89C52 chip, each competitor may build theirown Line Tracking Sensor, some may use LM339 QUAD comparator with IR transmitterand receiver, some may use LDR as described in LineFollower Robot. With an external comparator, it may not necessaryto have ADC, but with LDR, we need external ADC. " Having additional ADCfor 89C52 would be better", I thought. How can we provide ADC for 89C52with a cheap method I chose PIC16C711 with 4-channel ADC, and 7-pin inputport. Interfacing to...
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....
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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....
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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.....
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