# BEC for HV servos – Mini 560 quick mod

> Turn a sub-$1 Mini 560 DC-DC step-down into a 4 A, 98%-efficient HV BEC for RC servos: add a 100k resistor to get 8.1 V from the 9 V version.

- URL: https://guillaumeplayground.net/bec-for-hv-servos-mini-560-quick-mod/
- Author: Guillaume (https://guillaumeplayground.net/about/)
- Published: 2022-09-18
- Updated: 2022-09-19
- Section: RC & builds
- Topics: drift, glider, rc, sailboat, scaled glider
- Source: Guillaume playground

Looking for an efficient and powerful HV bec for your servos and receiver(s)?

The Mini 560 DC-DC Step-down, which costs less than 1$, is able to output continuous 4A with 98% of efficiency from a 3S lipo (manages 2s to 4s).

The Mini 560 is available in 5V or 9V. A quick modification of a resistor allows to change the output current. You can either order a 5V or 9V… but the 5V modification is more tricky: SMD soldering.

![BEC for HV servos – photo 1](https://guillaumeplayground.net/wp-content/uploads/2022/09/H8be88a55beb6451485bfa4232a107099B-1.jpg)

With the 9V version, to output a solid 8.1V, just add a 100K resistor in parallel with the 14.3K SMD.  
You can use the 2 smd resistors side (circle in red) to solder. It is linked.

![BEC for HV servos – photo 2](https://guillaumeplayground.net/wp-content/uploads/2022/09/Ha89450c510ec4842a52bfe8442234cc9n-1.jpg)

![9V to 8.1V modification of the Mini 560.](https://guillaumeplayground.net/wp-content/uploads/2022/09/4096-2304-max.jpg)
*9V to 8.1V modification of the Mini 560.*

![9v to 8.2v modification with 100k SMD resistor over the previous one in parallel](https://guillaumeplayground.net/wp-content/uploads/2022/09/IMG_20220920_004725_8.jpg)
*9v to 8.2v modification with 100k SMD resistor over the previous one in parallel*

## More? redundancy and stability

Make it redundant with a second modified Mini 560 to 8.1/8.2V and add schottky 5A diode on each Mini560 \[+\] output. The schottky generates also a voltage drop of ~ 0.2V/0.3V. You have now a redundant BEC for 4$.

Make it more stable by adding a 470uF 16V capacitor on the output (after schottky’s output merge).