Four-way flashing light string circuit (2)

A four-way flashing light string controller cleverly uses a four-way gradually brightening and fading light-emitting diode driver integrated with iU . The HFC3484 integrated block produced by Wenzhou Shihua Electronics Co., Ltd. is a four-light fade-in and fade-out flashing chip specially used for Jiuang toys. It is packaged in a black paste soft package and has a size of 24 5 mm × 9 iimm. It is a time-programmable device. The input H1 terminal can directly drive a light-emitting diode or a transistor. The phase difference of each output is 90. flash.     VD, vs,C,,C blink R. It is composed of a simple capacitor step-down half-wave rectification and voltage stabilizing circuit. After power-on, it can output a DC voltage of about 3V for powering the integrated block HFC3-184 . The four output terminals Ql - Q4 of the integrated block input {fj negative pulses in sequence, and pass through R. ~ R. The external transistors VTl - VT4 are reversely amplified and turned into forward pulses to trigger the thyristors VT5 - VT8 in sequence to drive the road calling lights. Connect E1-E2_'E3- F:4--F:3- F.2 - - sequence It lights up gradually and dims gradually. As long as the four groups of colored lights are properly arranged in the space, a flowing water effect can be formed . The circuit RP and the resistor R connected between the RR terminals of the integrated block are sufficient to connect an external oscillation resistor. Adjusting the resistance of RP can change the flow rate of the light string. Table 8-1 shows the resistance value and its output cycle. time relationship . VTI - VT1 all use 9012 type silicon PNPj tubes, requiring p ≥ 100; VTo-VTS can use MCRIOO-S type and other small plastic-sealed unidirectional tubes (IA, '600V). The power of each group of colored lights from Fl to E4 should not exceed 1. . W is appropriate. RP uses wFj type small synthetic carbon film potentiometer, C, which requires CIm-4. Ov type polypropylene [U container, no special requirements for other components.     After debugging the circuit , it can operate normally when the power is turned on. In order to prevent the thyristor VT5-VTS from being disturbed and operating normally, a ceramic capacitor of OIRLF can be connected in parallel between the gate and cathode of each thyristor , and the fault will be eliminated.