Powering halogen bulb

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  • I am trying to power a low voltage tungsten halogen bulb using an MDBT42Q and an IRF3708 mosfet
    The lamp is a KANDOLite 6v 50w.

    Im trying to replicate the signal coming from another driver that successfully powers the lamp.

    The images with all statistics included is the original working solution.
    There is one image when the lamp is connected and one without the load.

    The image with fewer statistics is the signal from the drain pin in my solution.

    Generating the pwm signal with MDBT42Q feeding it to the mosfet gate and powering the lamp with 6v. But no luck. Is it even possible to do this ?

    3 Attachments

  • Take a look at @DrAzzy 's posts pertaining to MOS FETs How to use PICO with OLED and MOSFET? . He did extensive work and also sells on Tindie's https://www.tindie.com/products/drazzy/s­imple-sot-23-mosfet-six-pack-logic-level­/ . All the FETs he uses have a lower range of GS voltage for on. Since power (current) is obviously not an issue you may add a BJT drives the FET and MDBT42Q drives the BJT (w/ inverse logic, of course). The resistor values may be halved in first schematics, since the source were 5 and 12 Volts. The second schematics has the resistors to limit the Gate current and make sure that with open drain / float output the FET is off ( @MaBe , this time I was too lazy to go for character graphics... shoot and shop had to do it).

    2 Attachments

    • BJT_FET.png
    • FET.png
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Powering halogen bulb

Posted by Avatar for Gustav @Gustav