This interesting infrared gun circuit, the transmitting circuit is installed in the toy pistol or submachine gun, and the receiving circuit is installed on the target. The circuit is simple, the idea is novel, and the production is convenient. It can be used as target game or family toy in entertainment places. According to the characteristics of modern guns and the specific requirements of shooting games, the infrared gun is carefully designed and tested. Compared with the previous infrared gun game circuit, it has the following advantages: (1) good simulation and realistic shooting. When the trigger is pulled, a “bang” sound will be produced, and the muzzle of the gun will be illuminated at the same time. If you hit the bull’s-eye, the target will produce a few seconds of flash and music target sound（ 2) Limit the number of rounds. Through the opening and closing of the mini dip switch in the transmitting circuit, the allowable firing times are limited（ 3) Good anti-jamming performance.
Using frequency decoding technology, only the specific frequency signal transmitted by the transmitting circuit is allowed to be received, and other signals such as sunlight and lights are rejected.
1. Transmitting circuit
The circuit is shown in Figure 1. Ic1-1 and ic1-2 constitute a positive edge triggered monostable timer with a timing time of about 0.5s (t = 0.7xr3xc3). When S1 is switched, pin 1 of ic1-1 inputs high level and pin 3 outputs low level. Because the voltage at both ends of capacitor C3 cannot change suddenly, the power supply charges C3 through R3. At the beginning of C3 charging, pin 5 and 6 of ic1-2 are at low level, and pin 4 is at high level. After 0.5s charging, pin 4 of icl-2 turns back to low level to complete one shot control process.
Figure 1 transmitting circuit
There are two functions of the monostable timer: one is to take out the negative pulse from the ic1-1 (3) foot as the allowed firing counting signal of IC3 when the board computer S1 is pulled; the other is to take out the positive pulse from the icl-2 (4) foot and add it to the ic2-1 (1) foot of NAND gate. The allowable firing times are set by the micro integrated switch S2 (dip-10). For example, if each shooter has only 3 bullets, the yo ~ Y3 external switch of IC3 can be disconnected and the Y4 ~ Y9 external switch can be closed. At this time, close the power switch S3, and the automatic reset circuits R2 and C2 add a clear pulse to the IC3 @ pin, so that Y0 = 1 (high level), Y1 ~ Y9 = 0 (low level). In the first firing, pin IC3 (13) is triggered by negative pulse, Y1 = 1. The external switch is disconnected, and the external circuit has no effect. After R4 pull-down and ic1-3 reverse phase, ic2-1 (7) pin is 1, and ic2-1 (7) pin is 1 in 0.5s transient steady-state timing time. According to the logic relationship of NAND gate (y = a-b), its (3) pin outputs 0, and ic1-4 (11) pin is 1. The oscillator composed of ic2-2 and ic2-3 is selected to generate about 970hz (F = 1 / 2.2xr6xc4) oscillation signal. The infrared transmitter LED3 is driven by vt2 and VT3 to emit firing signal; The piezoelectric buzzer BL1 (htd27-a) is driven reversely by ic2-4 to give out a “beep”; At the same time, VT1 is turned on, and red LEDs LED1 and LED2 installed near the muzzle flash.
In the same way, because the Y2 and Y3 external switches of IC3 are also disconnected, the firing effect will be the same as that of the first time when the Si is pulled for the second and third time. After three shots, when S1 is pulled for the fourth time, Y4 of IC3 is 1. Because the external switch of IC3 is closed, pin 8 and pin 9 of ic1-3 get high level through the diode vd5. Pin 2 of ic2-1 is 0. Although pin 1 of ic2-1 is 1 in 0.5s, pin 3 outputs 1 and pin 11 of ic1-4 is 0. LED1, LED2, LED3 and BL1 do not work. In the same way, because the y4-y9 external switch of IC3 is also closed, it is still invalid to fire after pulling the trigger.
2. Receiving circuit
The receiving circuit is installed on the target, as shown in Figure 2.
Figure 2 receiving circuit
IC4 is a decoder LM567, including quadrature phase detector, PLL, amplifier, etc. C5 is the output filter capacitor, C7 is the low-pass filter capacitor, R13 is the output pull-up load resistor, RP and C8 determine the receiving decoding frequency (F = 1 / 1.1xrpxc8). The light shooting signal received by vt4 is converted into electrical signal (970hz) and input to C9 and IC5. IC5 is a double board single time base circuit connected to a monostable flip-flop. Due to its large output current (up to 200mA) at pin 3, it can directly supply power to LED 4 ~ led 6 and IC 6 (vt66a).
If the frequency of the signal emitted by the light gun is consistent with the receiving and decoding frequency set by RP and C8, the pin of iC4 (8) jumps to low level, the pin of IC5 (2) is triggered to enter the transient steady state, and the pin of IC5 (3) outputs the commercial level to make led4-led6 flash, indicating that it has hit the target. At the same time, IC6 outputs music signal to drive loudspeaker (8) via vT5 Ω/ 5 W) BL2 makes a loud music target sound. Acoustic and optical target reporting time is determined by IC5 transient steady state time (t = 1.1xr14xc10).
3. Installation and commissioning
The design of transmitting and receiving printed circuit board is relatively simple, and the size can be determined according to the actual matching toy gun and target. After all components are installed and checked to be correct, debugging can be carried out. Turn on the power, aim the infrared gun at the target center, buckle the board, and adjust the RP to make the output of pin iC4 8 low level. Then continue to extend the shooting distance, fine-tuning RP to make the longest range, generally more than 5m.