LED Lights circuits with LM339, IC555

This circuit reproduces the opening light sequence now used by FISA instead of Formula individual racing. It may possibly befall used with slot car sets (such like HO shin up AFX/Life Like/Tyco sets) or else means of communication controlled cars. IC1, a 555 timer IC, is used as a meter pulse generator. Its output is fed via NAND gates IC2a and IC2c to IC3, a 4024 binary counter. IC2b inverts the O4 output of 4024 binary counter IC3. at first, IC3 is reset and all its outputs are low, together with O4, which causes IC2b to grant a commonsensical climax to the pin 8 input of IC2c which afterward passes pulses from the 555 timepiece circuit to the clock input of the 4024. IC3 then begins including.

Similar to the count has reached binary 1111, the then pulse sends the O4 output of IC3 high, which disables IC2c and IC3 stops together with. The four used outputs of IC3 are connected to a resistor ‘ladder’ which acts because a undemanding digital to analog convert-er (DAC). As the count increases so does the voltage produced by the top of the ladder and this is connected to the inverting inputs of four comparators inside IC4 (an LM339) and to IC5, which is a 741 op amp besides connected for instance a comparator.

LED Circuit with Timer 555

The certain inputs of the comparators are connected to the taps of a voltage barrier, with the drumming voltages frozen using VR1, a 100kO trimpot. As IC3 counts, the rising stepped voltage from the DAC ladder switches the comparators on during sequence, preparatory with IC4d and working up to IC5. because each one comparator is bowed on, its put together of LEDs is lit; essential LEDs 1 & 2, so therefore LEDs 3 & 4 and so on. at what time all five pairs of LEDs are lit, the after that pulse from IC1 moves the binary count of IC3 to 10000, so the DAC voltage drops back to zip and all LEDs are extinguished. by the same age, plus additionally stops, as the lofty on O4 causes IC2c to mass expand gate pulses. The circuit it follows that remains stationary until the counter is reset by burning pushbutton switch S1. This allows a new-fangled sequence to kick off.