Power and Wiring
No, the power supplies in the in our monitors are not isolated.
The signal GND is low impedance to 28V GND.
All of the internal workings of our products use the internal wiring for 28V DC ground, as well as for chassis ground.
Most of our products have metal casings which, when installed, provide a common potential between product and plane.
The few products that are solely encased in plastic (FD900X3 or FD900X5 Wireless Transmitters, etc.) would just use the 28V DC ground as the chassis ground.
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.
Some of our larger LCD monitors use the latest LED backlight technology which uses significantly less power than prior LCD components.
The FD320CV (32-inch Aircraft LCD) at 28V DC power draws only 5 amps.
The fuse should be rated for 7.5 to 10 amps for the breaker. This is because there is a rush of current during boot-up. After one second, the power requirement will stabilize to 5 amps consistent load.
Lone Star Aviation has a 28V DC to 14V DC converter [PN LS03-05001, Phone: 682-518-8882].
Dallas Avionics also has a solution [Astron Power Supply P/N N2412-12, Phone: 800-527-2581].
The amount of current the FD151CV-LP continuously draws depends on the back-light level set by the user.
If the value of the back-light level is 100% (Maximum setting), then the FD151CV-LP draws a maximum of 1.5A @ 28V.