Description:

This board has two switched and fused relay buses that are controlled with 5V TTL signals. It also features a onboard 1A 5V switching supply, 50A current monitor, and status LEDs. We recommend using this on our ATRs where more than one battery will be used to drive the robot. It allows a lot of flexibility when hooking up your batteries while providing the fuse protection in one simple package.

The board can be powered by using a simple low current switch. The two power relays can be turned on using a TTL input or by placing a switch from the onboard 5V regulator to the switch input. You can pull both relays in to drive your loads with both batteries in parallel or switch between one or the other battery. This is ideal if you plan on onboard charging, you can attach your charger to the load side of the board and charge one battery at a time by switching the relays. NiMH Batteries can be run in parallel, but should be charged individually, this board provides the flexibility.

As a final feature you can monitor the current you are using. The output of the current monitor is 0-5V and can be monitored to determine how much current is being used to prevent stalls or predict remaining battery life. The output current is 0.6V for no load so reverse current can be monitored (ie if your charging the batteries). 60mV/A is the sensitivity of the sensor.

This board comes fully assembled and tested.

Features and Specifications:

The image lists all the connections. It's just a simple relay switch for two batteries. Run the +V of battery 1 and battery 2 to the input terminals respectively. The batteries must be the same voltage, nominal 24VDC. Put a grounding lug on your robot that both the batteries connect to. Run a small ground to the board to the terminal marked G on the small header to power the regulator. Put a switch on the small terminals as indicated. When you close the switch the board will power. Applying 5V to small terminal marked Relay 1 and Relay 2 will turn on relays (this can be done with TTL input or just jumper/switch from the 5V terminal). When relay 1 is turned on the power +V from battery 1 will go to the terminal marked 24V outputs via the current monitor. When relay 2 is turned on, its power will go to the output terminal. You turn on both relays if you want to parallel the batteries. Measure the voltage on the current monitoring pin to determine current draw.