Microcap Excercise

Microcap Exercises \Analogue\Microcap.docx

Range 1. Placing components, editing circuits. Generic/from library. 2. Signal sources. Sine, pulse. 3. Analysis – Time and frequency domain. Setting ranges. 4 Result output. Exporting images to Word. 5. Odds. Slide resistor. Stepping.

Class Exercises 1. RC LPF (charging circuit, t domain. Fixed source, pulse) 2. RC LPF (f domain) 3. FW bridge power supply (t domain) 4. OpAmp circuits – f and t. Operating point.

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 , the

smoothing capacitor is 4700 F and the load is 15 . 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 k resistor, all

connected in parallel, is driven from a source having a 100 k 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.

Answers

10(Vout – 11.2) gives Ripple = 5.045 – (-5.510) Average = 11.15 Ripple = 1.053 Vpp Time constant = 1.82 ms

Resonant frequency = 15.915 kHz. Gain = -20.835 dB (= 1/11 = 0.909) Phase = 0.483°.