Daily DIY

This is a lovely project for home constructors keen on building their own test and measurement (T&M) equipment. It makes use of the ICL8038 signal generator chip, manufactured by Intersil. An improved version, made by Exar corp. is available (XR8038A). It can be used to produce three types of waveforms, sine, square and triangle. The frequency, amplitude and duty cycle can be varied, and selection of waveform is done digitally. To further reduce the complexity, a 3-to-1 switch may be used in place of the digital selection circuitry. I made use of the digital selection mechanism because switches available on the market are prone to dirt accumulation and poor contact quality. Besides, the digital method is a lot cooler!

This project considers the development of a 70W Hi-Fi Power Amplifier for use as part of a Hi-Fi separates music system. The design is a fairly simple circuit topology, which is easy to understand and the author believes that the finished result sounds very nice indeed. The web posting is developed from an original design document available in pdf below. The detailed design issues are discussed in the pdf, while this posting discusses the more practical issues involved in producing the amp.

This is an advanced battery charger design based on Maxim’s battery charger IC MAX712. This device can, using a minimal set of external components, fast-charge an NiCd/NiMH rechargeable battery. Fast charge is terminated using several detection methods, including dV/dt, dT/dt and a time-based cutout. Full details can be obtained from the MAX712 datasheet, available at the Maxim Inc. Website

This is the first part of a set of articles charting the history of electronics from the very beginning to the present day. This article covers the first observations of electrical phenomena to Benjamin Franklin’s famous kite experiment.