Proportional controller circuit for remote control

Proportional controllers are used in various power remote control models to control the speed of the electric motor or the throttle of the oil engine. The set of encoding/decoding and control circuits introduced in this article can complete the above functions. This device performs proportional remote control by changing the modulation frequency of the transmitter. Figure 1 is the frequency adjustment circuit in the transmitter. Changing the size of the potentiometer RP can make the oscillation frequency change between 100Hz and 1kHz. Its output terminal is connected to the modulation input of the high-frequency transmitter. Figure 2 is the frequency/voltage conversion circuit in the receiver. LM2917 is used for frequency/voltage conversion, and the conversion distortion can be controlled within 3%. When the input frequency range is from 100Hz to 1kHz, its output voltage range is from 0.54V to 5.34V, with high linearity. Figure 3 is a proportional execution circuit for power motors. IC1 is a step-down switching power supply controller. When the voltage at the control input terminal changes between 0.5V and 5.4V, the voltage acting on the motor M changes between 3V and 12V. The pin of MAX1627 is the working state control terminal. If you still need to turn off the motor M, you can control it by controlling the potential of the pin. For example, use a voltage monitor to control the potential of the pin: the starting control voltage of the voltage monitor is 0.6V, higher than At 0.6V, IC1 works and M is powered; otherwise, IC1 is turned off. Figure 4 is an execution circuit for proportional control of engine throttle. Motor M is both a power motor for throttle control and a power motor for potentiometer RP. IC1 is a three-terminal voltage regulator, which outputs a stable voltage of 8V. IC2 is an operational amplifier, which forms a voltage comparator. The power output is handled by T1 and T2. IC3 is an audio power amplifier. Its non-inverting and inverting input terminals are connected to ground through two capacitors. At this time, its pin outputs half of the power supply voltage (6V). The pin of IC2 is connected to the conversion output of LM2917, and the pin is connected to the boom of potentiometer RP. When the pin voltage is greater than the pin voltage, the pin outputs a high level, T1 is turned on, and the voltage on M is left positive and right negative, which drives the RP's boom to move upward until the pin voltage is equal to the pin voltage; when the pin voltage is less than When the pin is turned on, the pin outputs a low level, T2 is turned on, and the voltage on M is negative on the left and positive on the right, which drives the boom of RP to move downward until the voltages on the pins and pins are equal. Motor M drives the RP boom and also drives the throttle switch. It requires M to drive the RP boom upward when the throttle is increased, and vice versa. During debugging, connect the voltage of 5.5V to the control input terminal, and adjust RP so that the voltage across the motor M is 6V.