This is a LED flash (see the attached picture), it does not flash during the day, using solar cells to charge the battery, and at night by the battery power. Give off a flash. Suitable for temporary construction sites and other fields cooperation warning lights. Flash circuit: RC oscillator is formed by IC1 and not gate.
If there is no R2 and D2 in the figure. This oscillator has a duty cycle of 50% and will consume more power at LED flash. After adding R2 and D2. The duty cycle can be adjusted by changing the resistance value of R2. When. When R2 is 68 kω, the duty cycle is about 5%, and when R2 is 33 kω, the duty cycle is about 2.5%.
LED drive circuit: the oscillation signal is output from pin 8 of IC1 to pin 12, and the signal of the overdischarge detection circuit is output from pin 1 of IC3 to pin 13 of 1C1: when the battery is not in the overdischarge state, pin 13 of IC1 is high, and pin 3 of IC2 will output the same oscillation signal as pin 1 of IC1. During the high level of the signal. Drive T1 on to make LED glow. If the battery is in an overdischarge state, then pin (13) of IC1 is low, pin (11) is high, and pin (3) of IC2 will be low, so that T1 is cut off and LED is not bright.
Overdischarge prevention circuit: The reset ASIC S-80819 is used for overdischarge detection. When the voltage between the second pin (input end) and the ground is lower than 1.9V, the output pin is low. That is, pin (13) of IC1 is low. LED cannot be lit. When IC3′s (2) and (3) interpin current exceeds 2.0V (1C3 has a 0.1V lag inside). The overdischarge state is discharged, and the output end (1) is in an open state. High level due to pull-up resistor R4.
Day and night discrimination circuit: use the output voltage of the solar cell to judge. During the day, the voltage of the solar cell is higher than the threshold of IC1, the IC1③ foot is low, the oscillator stops, LED does not flash, and the R5 in parallel with the solar cell is used to adjust the sensitivity of the day and night discrimination, and can prevent abnormal oscillation.
Solar cell selection of multi-crystalline silicon panels, the maximum output voltage 4.7V, the maximum output current 95mA; The battery is 4W2.5Ah; DI is the charging anti-reflux diode; LED is eight high light emitting diodes in parallel; IC1 and IC2 use 2 input 4 and non-Schmidt flip-flop 74HC132, and the unused and non-gate should short-circuit its two input ends and connect to the power supply “+” end.
Post time: Dec-25-2024