300W Subwoofer Power Amplifier (Updated) Rod Elliott (ESP) Share | Please Note: PCBs are available for this project. Click the image for details. Introduction There are some important updates to this project, as shown below. Recent testing has shown that with the new ON Semi transistors it is possible to obtain a lot more power than previously. The original design was very conservative, and was initially intended to use 2SA1492 and 2SC3856 transistors (rated at 130W) - with 200W (or 230W) devices, some of the original comments and warnings have been amended to suit. Updates 30 Jul 2003 - OnSemi has just released a new range of transistors, designed specifically for audio applications. These new transistors have been tested in the P68, and give excellent results. As a result, all previous recommendations for output transistors are superseded, and the new transistors should be used.

Do you really need CCTV? Closed Circuit Television is not the panacea to all security and safety problems that many people believe it to be. CCTV should only be part of an integrated approach that considers all aspects of the security problems being experienced. The starting point for any CCTV system must be the camera. The camera creates the picture that will be transmitted to the control position. Apart from special designs CCTV cameras are not fitted with a lens.

S EPTEMBER 2002 1 www.siliconchip. com.au Design by Frank Crivelli - Article by Ross Tester Last month we presented a 4-channel UHF remote control system.