Bosch Plena Dummy Load Board - Pack of 12

This greatly increases the dependability of impedance measurements, providing reliable break or short circuit detection, even on long wire runs.

• Provides filtered load at 20 kHz
• Makes longer loudspeaker lines possible
• Three power settings
• Fits on built‑in mounts on selected Bosch loudspeakers

To improve the performance of the impedance measurement Bosch Security Systems introduced the Plena Dummy Load. It increases the loudspeaker load at the monitored frequency of 20 kHz, while having a minimal load in the normal audio frequency range.

When connected in parallel with the last loudspeaker on a line, it will increase the percentage of impedance present at the end of the line, thus increasing the number of loudspeakers that can be attached. At the same time, it will also increase the margin for masking by cable capacitance, allowing longer cable lengths.

The dummy load connects in parallel to the last loudspeaker on a line, which must be a Bosch loudspeaker with the appropriate mounting studs. It has a jumper to set the load (at 20 kHz) to 8, 20 and 60 W, according to the results calculated by the Dummy Load Calculator.

The Dummy Load Calculator is a spreadsheet that uses macros to calculate whether an application can use a dummy load, and what the optimal load setting would be. The spreadsheet is available from all Bosch dealers.