Description.
This is a simple LED torch circuit based on IC MAX660 from MAXIM semiconductors. The MAX 660 is a CMOS type monolithic type voltage converter IC. The IC can easily drive three extra bright white LEDs.The LEDs are connected in parallel to the output pin 8 of the IC. The circuit has good battery life. The switch S1 can be a push to ON switch.

Circuit diagram with Parts list.

led-torch-using-max660

Notes.

  • Assemble the circuit on a general purpose PCB.
  • The IC must be mounted on a holder.
  • The circuit can be powered from two torch cells connected in series.
  • The capacitors C1 and C2 must be Tantalum type.
  • The diodes D1 to D3 must be of 1N4148.
Author

19 Comments

  1. How can i download the circuit diagram of led torch.

  2. Seetharaman

    Hi Kiran and Surendra the maximunm output drive current is just 100mA at a max of 5 volts. Hence it is not possible to drive beyond 300 to 350mw LEDs.

  3. Surendra Biyani

    Can MAX 660 in my LED of 1 watt be suitable to withstand 7 volts DC current. My requirement is to get 30 lumens of focussed light.
    Any heat will be generated ? If so then I may use a heat -sink

  4. @Taimur, Led’s may not glow even in 3V supply! Cause different LED’s Have different drop out voltage( The minimum forward bias voltage to turn the LED on). For white LEDs, it’s higher than the 3V. Max 660 can derive -3V from the supply at pin5. so in the circuit, across the pin 5 and 8, a voltage difference of 6V is available. It’s sufficient to turn on the LED and glow it!

    @Srihari Rao, you can search for LM7660 IC too. It has similar functionality to that max 660!

  5. I didnt get one thing , if I can light up the LEDS using 3V battery directly then what advantage am I going to have by using the MAX 660 IC ? Please explain

  6. CAn I ask a few question?
    what is the function of led torch using max660?please answer As soon as possible!!we badly needed it for our project!!!thankyou!!

  7. where we can apply this circuit led torch using max660?

  8. Dipankar

    MAX660 is costly.
    The cheapest method is to make a Joule Thief Circuit which uses only a 1.5 volt battery and can run 4 LED’s.

  9. max660 is too much expensive in my market is there any cheap replacement of this ic?

  10. seetharaman

    hi Adnan you are right it is an application of max660 to generate equal negative voltage from input positive voltage, so with 1.5 volt input you can get -1.5 volt. with 1.5 volt you can operate 3 high brite white leds (ic capacity 100mA max), 3 leds torch operating just with a single cell. reader can refer the datasheet.
    http://datasheets.maxim-ic.com/en/ds/MAX660.pdf

  11. we can glow these 3 leds directly from the 3 volts battery then why we use the ic?what is the effect of ic and working tell me?

  12. i have the project of counter by labs and idonot about it please help me

  13. Sottapilla

    I am a new person to the electronic circuits, with minimum knowledge about the circuits. Kindly do publish the range of applications the circuits support, and also any more additions to the circuits

    with regards

    sottapilla