The following is the circuit diagram of a delay switch circuit designed using LM431. Delay Switch Circuit Designed with LM431 The working principle of this circuit is based on R1 and C1 forming a delay network. The desired delay time is set to 1 second, and for optimal performance, C1 should be a tantalum capacitor that can operate within a temperature range of -55°C to 125°C. Upon power-up, the input terminal of the LM431 is at a low level, which causes its output to rise to approximately 23 volts. This turns on transistors Q1 and Q2, allowing current to flow through the ignition coil for a short period, reaching around 24 amps. After one second, the voltage at the LM431's input increases to 2.5 volts. At this point, the output of the LM431 drops to about 2 volts. To ensure proper operation, a Zener diode (Z2) with a breakdown voltage of 6.2 volts is connected in series with the LM431’s output. This allows Q1 and Q2 to turn off, de-energizing the ignition coil. The ignition coil is an inductive load with a DC resistance of approximately 1 ohm and operates on a 24-volt battery supply. The measured current during operation is around 25 amps. The overall operating temperature range of the circuit spans from -40°C to 121°C, making it suitable for use in automotive electronics applications where reliability under extreme conditions is essential. (Editor: Circuit Diagram) Electric pole, also known as a telephone pole or telegraph pole, is a tall structure used to support overhead power lines and other utilities, such as telephone and cable lines. These poles, typically made of wood, metal or concrete, are installed along roadsides, in residential and rural areas to deliver electricity and other services to homes and businesses. The height and design of poles can vary depending on the specific requirements of the utility company and the location of the poles. Electric Pole,Distribution Steel Pole,Utility Pole,Electricity Pole JIANGSU HONGGUANG STEEL POLE CO., LTD. , https://www.hgsteelpoles.com
