Assessment
For each circuit and its analysis there should be graphs shown (in Word) and conclusions drawn about the circuit operation (c.f laboratory write-up).
1. Draw a circuit of a DC power supply having a 20 V (10 V + 10 V) centre-tapped transformer secondary and using a full-wave rectifier. Each secondary winding has a resistance of 0.5 Ω, the smoothing capacitor is 4700 μF and the load is 15 Ω. Use 1N4001 diodes.
(a) From the output voltage variation during turn-on calculate the turn-on time constant.
(b) Calculate the steady-state DC (average) output voltage and the peak to peak output ripple voltage. Include graphs.
2. A resonant circuit comprising a 1 mH inductor, a 100 nF capacitor and a 10 kΩ resistor, all connected in parallel, is driven from a source having a 100 kΩ resistance.
(a) Measure the centre (resonant) frequency of the circuit and its voltage gain (in dB and as a ratio) at this frequency.
(b) Describe the circuit's response to a 4 Vpp sinusoid. Measure its time constant.
(c) Describe the circuit's response to a 100 Hz, 10 Vpp square wave centred on 0 V.