Matt circuit

With the advancement in IC technology , a number of manufacturers now offer universal filters having simultaneous low-pass, high-pass, and band-pass output responses. Notch and all-pass functions are also available by combining these output responses in the uncommitted op-amp. Because of its versatility, this filter is called the universal filter. It provides the user with easy control of the gain and Q-factor. It is also called a state-variable filter. The filters we have discussed so far are relatively simple single op-amp circuits or several single op-amp circuits cascaded. The state-variable filter, however, makes use of three or four op-amps and two feedback paths. Though a bit more complicated, the state variable configuration offers several features not available with the other simpler filters. First, all three filter types (low-pass, band-pass, and high-pass) are available simultaneously. By properly summing these outputs some very interesting responses can be made. Bandpass fi...

As opposed to discrete designs, the IA502 uses an IC to drive the power stages. The entire power amplifier circuitry for 2-channels are squeezed into a tiny TDA7250 10-pin IC. All that's required are four power darlingtons and some passive components to complete a high performance stereo amplifier. No biasing is required as the IC auto biases the output transistors. The IA502 lends itself well to multi-channel amplification. A 6~8 channel power amplifier can easily be constructed even by beginners. The TDA7250cfp This 2-channel hybrid IC is normally configured with TIP142/147 power darlingtons for its' output. For those who prefer to use power transistors instead, the TDA7250 can easily be converted. All that is required are a few transistors, 4 additional resistors and some rewiring. This conversion centers mainly on changing the output section to a Sziklai. Sziklai Output In our IA502 on the right, drivers Q1,Q2 are 2SC2238 and 2SA968, and outputs Q5,Q6 are 2SA1216 and 2SC292...

This circuit demands a control current that is 100 times smaller than that needed by a typical optically isolated solid state relays. It is ideal for battery-powered systems. Using a combination of a high current TRIAC and a very sensitive low current SCR, the circuit can control about 600 watts of power to load while providing full isolation and transient protection. Sourced by :link

This circuit demands a control current that is 100 times smaller than that needed by a typical optically isolated solid state relays. It is ideal for battery-powered systems. Using a combination of a high current TRIAC and a very sensitive low current SCR, the circuit can control about 600 watts of power to load while providing full isolation and transient protection. Sourced by :link