Homemade wireless remote control circuit diagram
Posted on Mar 28, 2007 7676
As shown in FIG homemade wireless remote control circuit diagram; A motor remote road works Wireless remote control transmitter circuit As shown for the remote control transmit
ter. Manifold 555 and R1, R2, RP1, VD1, VD2 and C1 form a wide range of variable duty cycle astable oscillator. Oscillation frequency parameter is shown around 50Hz, by adjusting the resistance RP1, vary the duty cycle of up to 1% to 99%, by the pin output 50Hz square wave signal. VT1 and external components, crystal frequency stabilization capacitance three-point oscillator, the resonant frequency of the quartz crystal selection 27.145MHz. The quartz crystal frequency stabilization circuit, so reliable. VT1 modulated square wave signal generated by the oscillation circuit 555 via the high-frequency carrier feet from the antenna out. Second, the choice of components Available 10K L1 type skeleton in the week, with µ0.15 high strength enameled wire around 9 turns, L2 with the same model in the outer wire 3 turns of L1, without shield, but need screwed core. L3 with L1 production. B with JAl2 other metal shell resonator frequency between 27-29.8MHz. VT1, VT2, VT3 are made 3DG130D type NPN transistor, 100. VT4 selection 3DD15D-power tube. RFC by 18uH inductors color code. IC1 model for NE555. IC2 model for the LM386. Unless otherwise specified capacitance electrolytic capacitors are used outside the high-frequency ceramic capacitors CC1. Resistors are made of 1/8w carbon film resistors. Third, debugging circuit To emphasize the transmitter carrier frequency oscillator, high-frequency choke coil B crystal and RFC temporarily installed, make C4 a short to ground. Adjust R3 resistance, so that VT1 collector current of 12mA, then install the crystal B, this time the current will increase to about 15mA, or should be carefully adjusted core L1 until the start-up circuit, remove C4 short route. Super-regenerative detector debugging method is to use a high-impedance headphones 800 series with a 10uF capacitor connected across the emitter and collector VT2, with no sense of screwdriver potentiometer RP2 fine tuning coil L3 and core, until the headset in obviously resounding rustling sound. Next to the transmitter antenna near the receiver, turn pass control switch S, to fine-tune the transmitter and the receiver coil core, until the headset can be heard clearly frequency sound stops, then pull away from the two planes, and then further fine-tuning. Rest of the circuit without debugging, you can work generally installed after.