Motorola T5422 power supply

Discussion in 'The Projects Forum' started by linky, Mar 4, 2006.

  1. linky

    Thread Starter New Member

    Mar 4, 2006

    I am using a Motorola T5422 PMR446 radio for Bike to Bike communications. The only problem is that the battery does not last that long and would like to run it from the 12V system on my motorbike.

    The radio works at 4.5v and 500 milli amps. (also runs with a 3.6V NiCad battery)

    Can anyone advise me on how to create a suitable, stable, drop down convertor so I can use the motorbikes powersupply.

    Thanks, Dave
  2. hgmjr

    Retired Moderator

    Jan 28, 2005
    I would suggest you consider using a 12v-to-5v dc-to-dc converter module.

    Digikey has a 12V in /5V out manufactured by TDK. The part number is CC3-1205SF-E. Cost of the module is $12 US. You will need at least two so that will allow you to meet the minimum purchase amount. I think Digikey requires a minimum order of $25 US.

    Since it is a printed circuit board mounted module you will need to mount it to a board, mount the board in an enclosure and do some wiring but it should work nicely.

    This module is a 3.0 watt unit so it should be ample power for your 2.5W radio.

    You could use a linear regulator but the efficiency would be poor and you would have to deal with the heat of the power dropped across the regulator.