Air-mode motor proportional drive circuit

This article introduces a unidirectional motor proportional drive circuit for electric air model power motor control. The components are easy to purchase, the circuit is simple, and the cost performance is high. It is very suitable for aviation model enthusiasts with a certain foundation of electronic technology to make their own.

Working principle :

D3, R8, R9, C5, TR1, and IC1B form a pulse widening circuit. The pulse signal output by the receiver is sent in by J1-1, and after comparison and widening, it is sent out from pin 7 of IC1 to drive T1 and T2. When the pulse signal is widened, the motor power-on time is extended and the speed increases, otherwise the speed decreases. TR1 is used to adjust the cutoff point of the motor. R1~R5, CI, L1, D2, and IC1A form an oscillation boost circuit, and a voltage of about 25V is obtained on C3, which is sent to T1 and T2 through R6 and R11. During the cutoff period of pin 7 of IC1, T1 and T2 are saturated and turned on. U2 is used to prevent the output voltage of the boost circuit from being too high and damaging T1 and T2. R7, R10, R12, U1, T3, T4, and D2 form a voltage detection protection circuit. When the battery voltage is lower than 5.2V, UI and T4 are cut off, T3 is turned on, and the driving voltage of T1 and T2 is pulled down. T1 and T2 are not conducting due to the lack of driving voltage, and the voltage of U1 is also pulled down by T3 through D2 to lock the circuit. When the battery voltage is too low, the motor is turned off to maintain the normal power supply of the receiver and each servo. Ensure the safe recycling of the model. IC2 stabilizes the battery voltage at 5V and supplies it to the circuit and receiver. L1 and CD4 are used to prevent interference between the motor and circuit and affect the normal operation of the receiver.

Component Selection:

IC1 uses dual op amp LM393. T1 and T2 use RRF60N06. It is best to use small components for resistors, capacitors, and transistors. The entire circuit can be installed on a small printed board of 4X3 square centimeters.