In almost all cases, our max voltage is 29.99 Volts. We have an overvoltage protection circuit that triggers between 30.0V and 38V.
The Technical Support team has recently informally tested all of the LCDs. The 5-inch and 7-inch displays worked fine with 13V – 29V. However, the larger aircraft LCD monitors needed at least 20V to start.
A safe rule of thumb for all Flight Display Systems equipment would be 26V – 29.5V. That covers even our most power-intensive larger LCDs.