Working principle: The gas sensor and W1 in the figure form a gas detection circuit, and the AC 5V voltage output by the power transformer heats the heating wire of the gas sensor. The inverter F1, W2'...

The circuit is shown in the figure, which consists of a pyroelectric infrared sensor, an interlocking monostable trigger and an analog voice circuit. IC1 and IC2 use the integrated pyroelectric infrar'...

The attached figure is the circuit diagram of the alarm. In the circuit, the electric heating element inside the sensor is connected to the 5V power supply through a 15Ω current limiting resistor R2. '...

After connecting a 6N8 to drive a FD422 single-ended tube amplifier, the circuit did not work properly. Checking the voltage on the cathode of 12AU7, it was more than 20 volts (the voltage did not dro'...

Using photocouplers in audio amplifier circuits not only isolates signals and prevents inter-stage interference, but also amplifies audio signals. Photocouplers can be used in circuits...

The circuit shown in the figure is a simulated karaoke accompaniment amplifier circuit. Based on the characteristics of the recording tape, this circuit can remove the same part of the left and right '...

The figure shows the typical application circuit of LM4911 for dual-channel amplifier. The left and right channel audio signals are input into the 1st and 5th pins of LM4911 (MSOP package) respectivel'...

As shown in the figure, this is the LM4901 audio power amplifier circuit (MSOP package). After the audio signal is input, it is coupled to the inverting input terminal (pin 5) of the amplifier through'...

As shown in the figure, this is the LM4915 dual-channel amplifier circuit. The left and right channel audio signals are input to the 8th and 3rd pins of the LM4915 respectively, and after being amplif'...

The AC-DC constant current LED driver circuit based on ZD832 is shown in Figure 1. When the AC input is 110V (85-125V), the IC pin VSEL (pin 15) should be connected to HVCC (pin 16); when the input is'...

The voltage of a nickel-metal hydride battery is only 1.2V, while the ultra-bright LED requires an operating voltage of more than 3.3V to ensure sufficient brightness. Therefore, we must try to increa'...

As shown in the figure, the RTD uses a Pt100 thermocouple. When the temperature is 100-600oC, the output current of XTR112 is 4-20mA, and the output voltage of RCV420 is 0-5V.

Place the alarm in the item you are carrying. When you forget where you put the item, or when you are away from it for a certain distance because the item has been stolen, the alarm will sound. The al'...

Combining the new features of DS18B20 and the new requirements of modern temperature measurement systems, this paper proposes a design scheme for a high-precision, multi-point temperature measurement '...

This circuit provides a constant current to the LED. The current through the LED depends on the value of resistor R2. Assume R2 is 560Ω. When 1 mA current passes through R2, a voltage of 0.56 V will b'...

Kaiyu brand intelligent switching power supply (also known as universal power supply module) can be used for the maintenance and replacement of 14-inch to 34-inch color TV, VCD, DVD and satellite rece'...

The proximity sensor introduced in this article has a light-emitting circuit that emits infrared light modulated by pulses, while the receiving circuit uses a filter to detect only the required freque'...

This good FM transmitter for stereo or any other amplifier will give you good signal strength up to 500 meters range with power output of about 200mW. The circuit can be powered by 9V battery.

The picture shows a car radio circuit with the ULN-2242A intermediate frequency amplifier integrated circuit as the core. Switching between amplitude modulation and frequency modulation is achieved th'...

This article introduces a mobile phone emergency charger that uses two AA alkaline batteries or rechargeable batteries. After being boosted by the circuit, the mobile phone is charged by direct chargi'...