This wireless doorbell is an electronic product analyzed by the author. The wireless doorbell button together with the transmitter is embedded in the wall next to the door, and the receiver can receiv'...

The multifunctional wireless nursing help-seeking device is composed of a transmitter and a receiver. The transmitter is designed to wirelessly transmit four help-seeking information, namely, eating, '...

This electronic hypnotist is made by utilizing the calming and tranquilizing effect of white noise, and its effect is better than the monotonous raindrop sound hypnotist.

The author found many tubes, among which there is 6AS7, which is a double triode tube, often used as a voltage regulator in the electronic tube power supply. It has a large output current and a very l'...

The circuit is shown in the attached figure. The circuit is powered by capacitor Cl step-down, 12V voltage regulator 1N4742 voltage regulator, diode D1 rectification, and capacitor C2 filtering. When '...

This is a metal detection circuit, which can detect coins or metal pieces under the carpet. This small device is very suitable for hands-on self-help. 1. Preparation of components In the circuit...

The curtain remote control device made of radio remote control special receiving and transmitting components has simple circuit, stable and reliable operation, high cost performance; and can realize "'...

Professional tachometers have complex circuits and are expensive. General enthusiasts are restricted by economic conditions and cannot afford to buy them. The author has designed a simple electric tac'...

DKl000R is a receiver module composed of RF2519 receiver chip and rolling code ***. It complies with FCC 15.231 standard, and its matching transmitter module is DKl000T. DKl000R is suitable for...

As shown in the figure, this is a precision unit gain inverting amplifier circuit. This circuit connects pin 1 to pin 3 and grounds them. Two 25kΩ resistors are connected in parallel inside. The signa'...

The figure shows the recommended circuit for different power on time of LM4911. This circuit uses a controller to use the MOSFET tube in the controller to control the shutdown control (SD) terminal of'...

As shown in the figure, two NE566Vs are used to form a low-frequency FM generator. In the figure, ICl NE566V is used to generate the modulation signal, and IC2 works on the carrier signal. Ctl is sele'...

Constant current source circuits are indispensable in lighting fixtures and battery chargers. The attached figure shows a constant current source circuit composed of two PNP transistors and four resis'...

The amplifier circuit of this machine is composed of 6N11SRPP+6N8P cathode output; the high voltage power supply is 220V full-wave rectified and filtered by RC to obtain 260V high voltage: the filamen'...

In actual production, the bridge connection method is often used, which can save two output capacitors that are easy to affect the sound quality. Figure 1 is a circuit diagram of a channel. In actual '...

When a finger touches the ON electrode, the circuit detects the skin resistance and provides a very small current to the composite transistor to open the circuit and turn on the 6V small lamp.

Although the TOP22X series came out earlier, it has simple peripherals and high efficiency, making it suitable for beginners. The figure below is the real data of mass production. The transformers are'...

A quick look at the circuit schematic shows that it is almost the same as a general op amp circuit, but the resistors and capacitors have changed a lot, and the working state is different from the op '...

The FU-50 single-ended Class A 7W amplifier circuit is shown in the attached figure. The maximum second grid voltage limit is 250V. 150V is selected in this column. However, this voltage must not be s'...

This article introduces a sound-controlled light-controlled energy-saving lamp composed of common electronic components. It is very suitable for beginners of electronic technology to make small projec'...