Minimum Logic Battery Voltage
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Basicmicro Support
- Posts: 1594
- Joined: Thu Feb 26, 2015 9:45 pm
Re: Minimum Logic Battery Voltage
1. Logic battery has a minimum voltage limit of 6v as shown in the product datasheet specification table.
2. LB/MB pins are on older boards. The next sentence after the quote you posted says that on newer boards there is no LB/MB pins and the logic battery is automatically selected when used.
3. When it says reset it means to power cycle the board. Errors(as apposed to warnings) are usually caused by significant over temperature, or voltage outside the specs on the board. Both of which require the unit to be shutdown and the problem to be corrected.
4. USB never supplies power to the boards. The USB 5v is only used to indicate to the Roboclaw that the USB cable is connected. No significant current will be drawn from the USB cable. If LB+- is powered the logic circuit will remain on even if no power is on the main battery input. However if you try running the motors while main battery is disconnected you will get an error since main power alone powers the motor driver circuits.
2. LB/MB pins are on older boards. The next sentence after the quote you posted says that on newer boards there is no LB/MB pins and the logic battery is automatically selected when used.
3. When it says reset it means to power cycle the board. Errors(as apposed to warnings) are usually caused by significant over temperature, or voltage outside the specs on the board. Both of which require the unit to be shutdown and the problem to be corrected.
4. USB never supplies power to the boards. The USB 5v is only used to indicate to the Roboclaw that the USB cable is connected. No significant current will be drawn from the USB cable. If LB+- is powered the logic circuit will remain on even if no power is on the main battery input. However if you try running the motors while main battery is disconnected you will get an error since main power alone powers the motor driver circuits.
Re: Minimum Logic Battery Voltage
I noticed this on some newer boards I just got, and figured I'd revive the old topic....IMC Support wrote:2. LB/MB pins are on older boards. The next sentence after the quote you posted says that on newer boards there is no LB/MB pins and the logic battery is automatically selected when used.
The automatic selection between LB/MB actually causes an issue on one of the robots we're using the older RoboClaws on. This robot is battery-powered, and needs to be running for hours/days/weeks on a single charge. We've been connecting MB directly to our always-hot battery power rail as expected, not supplying any LB, but supplying switched 5V through the servo header. The RoboClaw doesn't draw any current through MB when the 5V is off, and in this way we don't have to switch on/off the high current MB supply, just the low current 5V.
Is there any way to turn the new RoboClaws completely off now? Or will we have to start switching the MB supply? Thanks.
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Basicmicro Support
- Posts: 1594
- Joined: Thu Feb 26, 2015 9:45 pm
Re: Minimum Logic Battery Voltage
You will have to provide an external contactor/relay to disconnect the MB power. There is no way to switch off the power from MB on the Roboclaw so there is always some power draw(milliamps) when power is connected to MB.