Light effect consists of two nested hearts made of 40 red LEDs, which are switched on alternately.The effect of dynamic, vivid and very attractive.The device demonstrates the beating of the human heart.
The device consists of a generator of rectangular pulses collected on the integral timer 555, power switches and 40 LEDs arranged in a heart. The operating frequency of the generator is set by the resistors R4, R5 and the capacitor C1. The transistor switches Q1, Q2 commute LEDs to prevent overloading of the output stage of the chip U1. The diode D17 prevents the device from damage, improper connection of the power supply.
Specifications:
Supply voltage: 9 V
Current consumption: 50 mA
Diagram of the device:
PCB:
List of elements:
R1 is 20 ohms
R2 8,2 kOhm
R3 - 1 kOhm
R4, R5 22 Ohm
C1 - 22 µf/16...50
VD1 - 1N4148, KD522
VT1 - ВС547, ВС548
VT2 - BC327, ВС557
DA1 - HA17555, timer 555
Properly collected scheme does not require adjustment, and begins to work immediately.
