6.5~8.7V boost board (9V standard battery)

This project is a manipulation board of the original fan switch circuit.

(original version)

The switch has 2 gears, the first gear is 6.6V and the second gear is 8.7V.

The default R5 resistance is 150K, R6 resistance is 15K, and R7 resistance is 110K.

Users can output the voltage you want by changing the resistor values ​​of R6 and R7. Calculation formula Vout=0.6*(1+R1/R2)

R5 150K remains unchanged,

First gear

R6 default 15K-----6.6V

Second gear

R7 default 11K -------8.7V

In addition, when moving components from the original version, you need to pay attention to the one-to-one correspondence.

After copying the board, rearrange the layout according to the size of the 9V battery.

Note: R6 is marked 05C, R7 is marked 18D.

The 9V battery terminals can be rotated and soldered directly to the board.

The batteries can be 082034, 802035, 502035, any of these models are acceptable. Batteries with or without protective plates can be used. There is already a battery protection chip on the board.

final effect: