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September 11, 2017 12:16

Will I have to put a resistor in series for this?

Hello, I wanted help with using a DC DC converter, I am adding indicators and a horn to my E-bike and The battery is a 60V battery which can supply a max of 30A i need to step down from 60v to 12v to run the led indicators and horn

I did have a dc dc converter before it had input voltage of 4.5- 60v and an output of 1.2 to 30v 15W when I connected this up to a 48V battery after adjusting the voltage at 12v it just popped I was under the impression that the device would have an in built current regulator.

so my questions, would this work for my application? and would I need to put a few resistors in series to get the current to where I would want it?

RS Stock No.122-4486

XP EMCO - JTE03 Series of DC-DC Converters

Mfr. Part No.JTE0348D12


thank you

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September 12, 2017 08:22

Hi scrachdat, my first question would be what will be the 12V load?
The part you list is +/-12V @3W so if you only require 12Volts half the power capacity is not used and you will have a max 125mA available.
The LEDs could have a wide range of current specs and as you mention indicators I assume these will be power LED's. Similarly the horn can have a wide current range and if electro mechanical type will be electrically noisy with current spikes which will require careful consideration.
Searching the RS options I would as you have done select a 36V to 75V input type and the appropriate power when known, there are many options listed to quite high currents.

Alternatively you may want to consider a design which uses a switch mode charger for a 12V battery where the added battery will provide the short duration current requirements. Batteries will normally have low impedance and high current capacity. This is just as a suggestion for you to consider.

Hope this helps

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