Description.
This is the circuit of a low power LED night lamp that will automatically switch OFF at day time. The CMOS timer IC TS555CN is wired as a square wave generator operating at around 5Hz.The output voltage from the IC1 is doubled using the combination of capacitor C2 and diode D2 in order to drive the LED. The LED can be a bright white LED. At day time the resistance of LDR drops to few K Ohms and inhibits the IC from producing oscillations.
Circuit diagram with Parts list.
Notes.
- Assemble the circuit on a general purpose PCB.
- The circuit can be powered from two 1.5V cells in series.
- Any diode can be used in place of D2, but Schottky diode like 1N5819 will give more brightness.
- The IC1 must be CMOS type because other types won’t operate at low voltages like 3V.
- An optional switch can be added in series with the battery ( not shown in circuit) to provide an manual ON/OFF.
13 Comments
Great circuit! I am thinking, is it possible to use rechargeable lithium polymer battery, once cell can get 3.7V instead of two, now its not big problem to produce round shape lithium polymer battery, can this idea help improve this system?
what about design and function of each element in the circuit
please send me very simple circuit within 10 components. …….
how can I replace ic in this circuit with any component actually I don’t wanna use ic
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I have seen this circuit numerous times and nobody can tell me that it works. Some say that it will work with one 1.5 volt battery because the 555 doubles the voltage, but the fact remains that the LED and diode still make the circuit stay lit without anything else being necessary.
The 220 uf capacitor guarantees that the 555 can NEVER turn the light off! at best, it can make it blink.
hey i am getting LED ON but its not responding to the LDR .. PLS SAY WHTS THE PROBLEM…….
I cant understand how the LED ever turns off. Won’t current flow from the battery through the LED through D2 even if the TS555CN is inhibted?
Hi Ask 7555 is the CMOS version of the standard NE555.
is there an ic 7555
I was wondering if any other IC could be used as i do not have any way of getting hold of the TS555CN
Hey there, neat website, just have something to ask you, what antispam software you use for cleaning up comments because I am getting tons on my site.
“Battery operated mini night lamp” is not working, time waste money waste dude worst circuit pls just remove this circuit
I think you have used a NE555 IC instead of the TS555CN. TS555CN is the CMOS version of NE555. Only CMOS ICs can work well on low voltages like 2V. I dont think there is any problem with the circuit.