Dual supply for this circuit.
A +15V/-15V dual supply for powering this tone control circuit is shown below. Bridge D1 can be made using four 1N4007 diodes. This supply is unregulated and its quite fine for this circuit. Anyway if you need to have a regulated one please inform me.
Power supply for tone control circuit
Notes.
Circuit can be assembled on a vero board or perf boad. Any way a PCB is the best option.
Use +15/-15V DC dual supply for powering the circuit.
IC1 TL072 must be mounted on a holder.
By changing the value of R1 and R2 the voltage gain (Av) of the preamplifier stage can be changed
Read more: http://www.circuitstoday.com
Inverting converter circuit using uA78S40
An inverting converter is a circuit which reverses the polarity of a given input voltage. For example if 5V DC is applied at the input of an inverting converter, the output voltage will be -5V DC. A 15V inverting converter circuit using uA78S40 is shown above. Ct (in the circuit C1) is the timing capacitor for the ICs internal oscillator, C3 is the input filter capacitor and C2 is the output filter capacitor. Both C2 and C3 must be rated at least 25V. Resistors R1 and R2 forms a feedback network which feed backs a portion of the output voltage to the non inverting input of the Ics internal comparator. R2 and R1 can be used to set the output voltage. Transistor Q1 is the external switching transistor. The collector terminals of the internal driver and switching transistors are shorted and connected to the base of the external switching transistor through resistor R3.
Notes.
uA78S40 must be mounted on a holder.
Peak output current of uA78S40 is 1.5A.
1N5822 is a 3A Schottky diode. Do not replace it with an ordinary PN junction diode.
Vout = 1.25 (1+ (R2/R1)) for step down converter.
Vout = (1.25R2) / (R1) for inverting converter.
Switching Regulator Vs Linear regulator.
The controlling element for a linear regulator is an active device ( either a BJT or FET) operating inside its active region.In a linear regulator the difference between the input voltage and output voltage is dissipated as heat by the controlling element. This reduces the power efficiency. The controlling element requires a larger heatsink .
For a switching regulator the controlling element which is an electronic switch (a transistor or thyristor) has only two states, either ON (completely conducting) or OFF (completely open). This means that no power is wasted across the switching element and this result in better power efficiency. A well designed switching regulator can have up to 85% efficiency. The controlling element requires a smaller heatsink.
