Posted on Thursday, January 27, 2011 • Category: Amplifiers
The following is a 70W amplifier based on a popular TDA7294 chip. Main technical characteristics of the amplifier are as follows: input resistance - 22 kOhm input voltage - 750 mV nominal output power at 4 ohms and THD 0.5% - 70 Watts Frequency Range - 20 ... 20000 Hz supply voltage - ± 27 V, quiescent current - 60 mA. The amplifier has a built-in thermal protection, and protection against overload and short circuit in the load. For "soft" switching amplifier is SA1. Switch can be powered from a bipolar unregulated power supply. Power AC Transformer - 250-A, the secondary winding should be designed to current than 5A.
Build Accurate LC Meter and start making your own coils and inductors. This LC Meter allows to measure incredibly small inductances making it perfect tool for making all types of RF coils. LC Meter can measure inductances starting from 10nH - 1000nH, 1uH - 1000uH, 1mH - 100mH and capacitances from 0.1pF up to 900nF. The circuit includes an auto ranging and reset function to make sure the readings are as accurate as possible ... [more]