This PC board does everything needed to run
the bike boom box. It provides a 15 watt-per-channel stereo
amplifier that can drive two 4-ohm marine or car speakers.
The amplifier uses the new Class D switching amplifier technology that provides over 85% efficiency and requires no heat sink for the power transistors. The entire power amplifier is in the tiny square chip!
This board works with either 14.4V Li-Ion or 12V SLA battery packs. The 2 Amp-hour Li-Ion battery pack gives about 4 hours of run time per charge at full volume; much more at lower volume.
The amplifier has a gain switch to match it to the music player's output level. The audio input is a standard stereo mini phone jack.
A battery charging jack allows easy connection to a battery charger or external power source. The battery and charging jacks are protected against short circuits and reverse polarity.
A USB jack provides 5V charging power to keep the music player's battery charged. Thanks to Lady Ada for figuring out how to make the generic USB charger work.
Battery and speaker connections are made with screw terminals for utmost reliability.
I'm not prepared to offer kits of this type of product, as the assortment of tiny surface-mount parts is a logistical nightmare.
I do sell assembled and tested boards - buy one below.
There are always people who would rather do it themselves. So I decided to publish the data to make the PC boards. It is assumed that you know what you are doing with regard to buying the parts and assembling the surface-mount board.
The Gerber files for the PC board are here.
The parts list is here.
The parts placement and panel cutout diagrams are here.
The schematic diagram is here.
The amplifier chip datasheet is here.
|The CDAMP board is no longer being sold.