stepping down from 12 volts

michael strohm said:

Need advice stepping down power supply from 12 volts dc at 3 amps to 6 volts dc at 3 amps using resistors

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A resistor will give the same efficiency as a linear regulator but without the regulation.
3V @ 6A will have a power dissipation (waste heat) of 18W to drop from 12V, which requires a hefty heat-sink and possibly a fan.

Much better to use a switching buck regulator which typically has an efficiency around 90% so would dissipate less than 2W.

Using resistors to drop voltage only works if the load never changes, 3A. As soon as the load changes the voltage will change.

Yes, you need to give far more details of exactly what you're doing - but unless the load is constant, and you want an in-built toaster, then resistors aren't the way to go.

Pretty simple low cost and has over T protection, and plenty of margin :



Regards, Dana.

danadak said:

Pretty simple low cost and has over T protection, and plenty of margin :

https://www.aliexpress.us/item/2255799926298895.html?spm=a2g0o.productlist.main.71.43dc4b5cJf8Qtx&algo_pvid=5cc9c5e2-ea60-472d-aabe-ff4a14b5bcd1&algo_exp_id=5cc9c5e2-ea60-472d-aabe-ff4a14b5bcd1-35&pdp_npi=3%40dis%21USD%212.13%211.81%21%21%21%21%21%40211bc71916822407946235695d0792%2110000000290785912%21sea%21US%21784751897&curPageLogUid=a9kr2NJewnCa

Regards, Dana.

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Nice one, and incredibly cheap.