Different control mode of desk lamp

1. Touch type:

The principle of the touch desk lamp /table lamp is that the electronic touch IC installed inside and the electrode sheet where the desk lamp / table lamp touches form a control loop. When the human body touches the sensing electrode, the touch signal is sent to the touch sensing terminal by pulsating DC current to generate a pulse signal, and then the touch sensing terminal will send a trigger pulse signal to control the light to turn on; if you touch it again, the touch signal A pulse signal will be generated by the pulsating DC current and sent to the touch sensing terminal. At this time, the touch sensing terminal will stop sending the trigger pulse signal. When the alternating current crosses zero, the light will naturally go out. However, sometimes after a power failure or unstable voltage, it will light up by itself. If you touch a paper or cloth with excellent signal reception sensitivity, it can also be controlled.

2. Brightness adjustable:

The working principle of the adjustable desk lamp/table lamp is to form a resistance-capacitance phase-shifting circuit composed of a resistor R2, a potentiometer RP1, and a capacitor C. Adjusting RP1 can change the conduction angle of the bidirectional thyristor V, thereby changing the brightness of the bulb EL. Resistor R1 is a current limiting resistor. The charging speed of C is also related to the parallel circuit. When R1 and RP2 are fixed, the size of the shunt is determined by the resistance value of the photoresistor RL. When the grid voltage rises, the brightness of the light increases, the resistance value of RL becomes smaller, the shunt increases, the voltage across the capacitor C rises slowly, the conduction angle of the thyristor V decreases, the output voltage decreases, and the brightness of the light decreases; on the contrary, when the power grid When the voltage drops, the RL resistance increases, the shunt decreases, the conduction angle of the thyristor increases, the output voltage increases, and the light brightness increases. In this way, the light brightness is automatically stabilized at the set value.