The ordinary refrigerator motor starting circuit is generally composed of a secondary winding and a thermistor (PTC) in series. This motor starting circuit has two disadvantages: (1) The PTC is in a h'...

Modification of the receiver (set-top box): Turn on the machine. First find the output end of the RF modulator. Connect a 2.2μF/50V capacitor to the RF output end. Connect the other end to the remote '...

As shown in the circuit diagram, the microphone signal is sent from the MIC1 and MIC2 sockets to the ③ and ⑤ pins of IC1 (JRC4558) through R1, C1, R8, C5 respectively, and is output from the ① and ⑦ p'...

The materials used are a power transformer and two output transformers from an old tube recorder L-601. Considering the load capacity of the power transformer and the need to improve the signal-to-noi'...

Close the start switch SB, add a low-level control signal to pin ④, and control the rise and fall time of the power switch through the internal circuit. In order to delay the output voltage transient '...

The following figure shows a 13/18V two-way switch, which is composed of two 13/18V single-way switches and a two-power divider. Circuit principle: The switching voltage input from the IRD1 interface '...

The FM transmitter circuit uses a frequency-stable phase-locked loop system. The frequency code input from pins 15, 16, 17, and 18 is decoded and phase-detected, and the control signal vco of the PLL '...

As shown in the figure, this is a common-phase audio power amplifier circuit powered by a split power supply of LM1877. This circuit uses a transformer and a bridge rectifier circuit to split the powe'...

Introduction At present, the main channels of high-power household audio power amplifiers all use OCI circuits for power amplification. Since this part of the circuit works in a high voltage, high cur'...

As shown in the figure, this is a general digital control offset adjustment circuit. The offset change is digitally controlled. The integrated chip DAC-08C is used as a 6-bit D/A converter. Pins ② and'...

As shown in the figure, the temperature sensor of this circuit uses a three-wire RTD. If a two-wire RTD is used, the resistor RLIN2 can be eliminated.

An ac-dc converter is a power supply device that converts alternating current into direct current. Simply put, it is a switching power supply that uses the PWM principle. The MOS tube generates a chan'...

The charger circuit is shown in the figure. A LM358 is used for charge and discharge detection. IC1a is used for charge detection, IC1b is used for discharge detection, and IC2 is LM555, which is conn'...

The experiment in this lecture mainly introduces how to use ATmega8 and LCD1602 liquid crystal display to form a digital frequency meter with a frequency measurement range of 1Hz to 4MHz. Through expe'...

The USB charger kit, also known as MP3MP4 charger, is shown below as a circuit diagram based on the real object. In order to simplify the circuit and achieve the purpose of learning, a 1 ohm resistor '...

The RH5RH/5RI series of fixed output switching regulators for boost are usually powered by only one or two batteries in portable electronic devices (typically MP3 players).

Here we take the BOOST circuit as an example. The BOOST driving method is the simplest (source grounding, no need for bootstrapping and isolation), and it can also provide a certain boost capability.

The circuit of this portable lamp is shown in the figure below. The lamp is powered by two nickel-metal hydride batteries, which are charged by a DC 5V power supply of the USB standard interface of th'...

This is the simple multi tone alarm circuit diagram. This is a low cost circuit which is simple and easy to build. The main components of this circuit are based on dual op amp MC1458 and LM380.

Beautiful digital clock with WiFi time collection function. 25-pixel WS2812B (aka Neopixel) LED light strip, ESP32 (ESP-WROOM-32) microcomputer. The back cover is specially designed for the short ESP3'...