Last month we introduced this innovative compact and powerful Portable Public Address amplifier based on the Philips TDA1562Q 70W class-H power IC. This month, we conclude with the description of the power supply, cabinet and PC board construction and the parts list.

As noted last month, the power supply is effectively a battery charger with the 7 amp-hour SLA battery permanently connected.

Since the charger has other uses and could be used in any situation where a float charger is required, we are describing its circuit operation and construction separately, on pages 64 and 65.

We're also detailing the box construction separately - you'll find this on pages 66 and 67. While we give detailed dimensions, this is not the only approach possible. We're sure some readers will come up with completely different ideas for the enclosures.