About the "Primary 24v sensor" on MCB 5.3

Hey, I received a new 5.3 board about two weeks ago, and it has this “Primary 24V sensor” on the front side, bottom left of the board. We applied some electrical tape to it just in case (that’s the black thing around it). So, I was wondering, can I use it to power up a LiDAR sensor, or is it reserved for another purpose? I couldn’t find any information about it in the MCB documentation.

Do not use the Primary 24V Sensor spade jacks as a power source. That set of contacts is for certain cases where a customer requires our ECB protection circuits instead of the default which is a fuse. Use of that for power is not supported except by direct case where we at the factory say it is your best option.

Normally the automotive fuse that goes between battery power and the large 50 pin P702 connector is called F701 and is on the backside of the board at top right but on backside and is called Secondary 24V Sensor power. This set of spade lugs is fed from the main fuse, F601, which is shipped as 30 amp fuse. Frankly I try to put in 10amp fuse in F601 which is far safer but of course we cannot reach full torque and so on but still normally 10 or 15 amp fuse is ok for most customers and safer than 30A.

I generally pull the fuse F701 because the battery power goes right to pins on p702 when F701 is inserted. Only fuse F601 is between this fuse and full battery power on the side of the battery.

If you do not use our sensor board then p702 is unused and you can get power from P702 pins but at limited current, should be ok for a Lidar. ONLY plug in for power on P702 with red battery cable disconnected. If you slip and it short you have massive current that can be a big issue in safety and in your electronics. Make sure p702 has no more than a 10 amp fuse. 5 amp would be even better.

The end 4 set of pins to the far right on P702 are going to have full battery directly across them (fused by both F601 and F701). You could get your lidar power absolutely straight from the battery on those pins. The upper 4 pins are MCB ground and the lower 4 pins are then all your direct battery.

IF YOU DO THIS I STRONGLY SUGGEST YOU USE A LOW CURRENT FUSE LIKE 5 AMP in F701 (assuming your lidar is under 5 amps of course).