Please could someone tell me how to connect this TVS diode?

Diver300 said:

I'm still not clear where the relay is connected.

Here is the schematic for the voltage reducer. The output voltage is Vbatt * R2 / (R1 + R2) - 0.6 V.

The current taken by the resistors will be Vbatt / (R1 + R2). With the ratios that you are wanting, R2 will dissipate more power than R1. R2 will dissipate R2 * (Vbatt / (R1 + R2)^2

The output voltage will reduce slightly depending on the current taken by the display. If G is the gain of the transistor, and the display takes a current of I, the voltage will drop by:- I / G * R1 * R2 / ( R1 + R2 )

You can try various values for R1 and R2. To reduce the voltage by 25%, R2 will be three times the value of R1.

If R1 and R2 are too low, they will take too much current and get too hot. If R1 and R2 are too large, the voltage will reduce too much from the current taken by the display.

Click to expand...

Thanks. So I can keep the 10k and change the 22k for 30k and maybe use 3x91k or 2x62k in parallel?

The relay connects to a specific output from the controller which was designed for a low powered front and rear light. Because this output is from the controller it can be switched via the display. It hasn't got enough capability to power the light directly with only 6V 500mA so it will be used to power a 6V relay instead. I plan to use a 24V step down powered from the battery which the relay can switch to give 24V 750mA to the light. I think the display cable is in series with the controller so all current it needs goes via the display first and therefore the voltage reducer you rigged up for me. I am not sure if this is wrong or not but I think this is right. I remember you said that the NPN would need to dissipate this as heat but I was wondering if there was anything else that seemed wrong?