4 1.5V led using 555 IC

This LED circuit is powered only by 1.5V cell using the 555 IC. The timer IC is operated in astable mode similar to voltage double circuit, where 1.5V is step up to around 2.5V. The circuit frequency is around 60Hz  and consumes very small power thus leaving it on is not a problem.
1.5V led circuit
Part List:

R1- 39 kilo-ohms
R2- 100 kilo-ohms
R3-10 ohms but if no light  or very dim, just short it
C1- 100nF
C2- 10nF
C3- 220uF electrolytic capacitor
C4- 100uF electrolytic capacitor
D1- preferably  schotky diode but ordinary diode like 1N4001 will do
555- use the CMOS type 555
LED- red, yellow and other low power led (do not use white or blue)
1.5V- any 1.5V battery

Note: You can use  555 timer calculator if you plan to change the frequency of the circuit.
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4 comments:

  1. AnonymousOctober 11, 2011 at 12:05 AM

    The 555 specifications call for a minimum supply voltage of 5V, so it won't work at 1.5V. The CMOS 555 will work with a supply voltage of 3V, so it should work if another cell is added in series with the 1.5V cell.

    ReplyDelete
  2. DH-gmOctober 11, 2011 at 1:48 AM

    Thanks for your comment.
    Actually LMC555 of National semiconductor works on 1.5V supply voltage

    ReplyDelete
  3. Acme FixerOctober 26, 2011 at 8:06 PM

    I searched for a low voltage version of the 555 and found that the Texas Instruments CMOS timer chip TLC551 is specified to work down to 1 volt and is pin compatible with the 555. The LMC555 may not work below 1.5V so if the battery voltage drops the circuit may quit.

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  4. DH-gmOctober 26, 2011 at 10:15 PM

    Thanks for the info!

    ReplyDelete

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