As shown in the figure, this is a multi-channel laser anti-theft alarm circuit. VT1, VT2, RL1, RP1, R1, K, and VD6 form a light-controlled switch. During the day, the photoresistor RL1 is in a low-res'...

In some occasions, a dual-limit automatic temperature control device is often needed. The author has made a dual-limit automatic temperature controller for atmospheric pressure boilers, which has been'...

The power-on delay output high level circuit is shown in the figure below. When the power is turned on, since capacitor C has no time to charge, pins ② and ⑥ of the 555 time base circuit are at a high'...

The automatic egg incubator circuit consists of a power supply circuit, a temperature/ventilation control circuit, an automatic egg turning circuit and a temperature indication circuit, as shown in Fi'...

The high-frequency oscillator shown in the figure can be used as a high-frequency signal generator. By selecting different capacitance values, a high-frequency sine wave can be generated in the range '...

The RXM-921/916/903/868/433-ES series receiver modules are receiver circuits with excellent performance-price ratio in small SMD packages. RXM-921/916/903/868/433-ES series receiver modules are receiv'...

XEl209 is a low-cost ultra-low power transceiver suitable for applications in remote control and short-distance data transmission. The main technical features are as follows: ?The operating frequency '...

XEl203 is a transceiver that complies with the European ETSl-300-220 and North American FCC Part l5 standards. It is suitable for automated meter reading (AMR), high-quality voice, music and data tran'...

As shown in the figure, it is a simple high input impedance dual wave linear detection circuit. This circuit compensates for the feedback level Vf shift by adding a diode to the negative feedback loop'...

Have you ever wanted to add an RFID tag security system or surveillance system to your home or office? An internet-enabled Arduino rfid tag reader. For just $20 more you can open your door automatical'...

The interface circuit between 74LS164 and 8051 microcontroller is shown in the figure below. When the serial port of the 51 series microcontroller works in the sending state of mode 0, the serial data'...

As shown in the figure, this is a high-reliability universal timing circuit composed of CD4060B. The timing time of this circuit can be from 1 second to 1 hour, and the switch S2 is used for three-spe'...

After repeated experiments, the author has made a reliable electric bicycle fast charger. The circuit is shown in the attached figure.

The circuit of the bookcase mothproofer is shown in the figure below. ICI and IC2 are CC7556 dual-time base circuits, IC1 and peripheral components form a monostable timing circuit, and IC2 and periph'...

As shown in the figure, this is an agricultural liquid level automatic control circuit. This control circuit consists of a step-down rectifier circuit, an RS trigger, a solid-state relay (SSR) control'...

The principle of the amplifier is as follows: the input end is connected to the antenna with a 75-ohm high-frequency coaxial cable, and the signal is first filtered by an FM bandpass filter to remove '...

This constant temperature controller has the characteristics of wide application, high precision, low cost, easy installation and adjustment, etc. The constant temperature controller consists of therm'...

Microwave control switches are widely used in automatic control, alarm and other fields. Q1, L1 and C1 in the attached figure form a microwave oscillator circuit, and L1 is both a transmitting coil an'...

For an amateur radio enthusiast, getting a good FM transmitter circuit is like picking up a treasure, but the circuit in the book cannot obtain sufficient transmission power due to many practical reas'...

The overvoltage protection and soft start function circuit introduced in this article is suitable for incandescent lamps and ordinary lamp holders. It has the functions of overvoltage protection, exte'...