This unit is designed for a smooth dimming with LEDs control with one button. The device is built on a chip CAP. This chip designed to create electronic touch control dimmer switches all functions with a single sensor. To turn on, turn off and install the required brightness of lighting used, the signal from the sensor or from external control device.
Structural diagram CAP shown in Fig.1. The chip is produced in a flat plastic DIP-16 (Fig.2A), the Pinout is shown in Fig.2B, and the pin assignment in table.
Diagram of the device it is shown in Fig.3.
When you press the SB1 LEDs HL1…HL15 start to glow at minimum brightness. If the button is held depressed for more than 0.5 s, the brightness glow cyclically changes from minimum to maximum. When release the button the adjustment process is stopped and set the brightness remains. Thus it is possible select the required illuminance.
On the elements DD1 chip built pulse generator. Those impulses are sent the input to CF (pin 2) of the chip DA1и start the internal oscillator of the chip. Parametric stabilizer R3-VD1 produces voltage of 12 V to power the chip DD1.
The circuit has resistors MLT-0,25, capacitors C1…C4 - type K10-17, C5 - K50-35. Button SB1 - any small (non-latching). Transistor VT1 you need to provide a small heat sink ("flag"). LEDs - white, high brightness, with operating current of 20 mA. The elements of the device placed on a small printed circuit Board (Fig.4A), the LEDs are arranged on a separate Board in the form an equilateral triangle (Fig.4B).
When soldering chip DA1 necessary to take measures for protection against static electricity. The power of the device is supplied from the stabilized source of 15 V/0,4 A.
Author: A. Levashov, Kizlyar, Dagestan