You may use Multisim
Construct a single phase, one-pulse SCR battery charger in Multisim. The same basic circuit
as in section 1 above can be used, but replace the diode with a SCR and include a 340VP : ≈
200VP (depending on your student number) step-down transformer between the ac supply
and the SCR. Implement your circuit in Multisim using ‘virtual’/ideal components. Also add
a 10-V firing/triggering pulse via a 10-Ω resistor to Gate and Cathode. You must have some
form of delay in the pulse to fire at a certain angle
Simulate typical output waveforms for the circuit (choose a firing angle α). Show voltage as
well as current – and use a current probe to send the signal to the oscilloscope. Briefly
discuss the waveforms to summarise the operation of the circuit.
• Now, from the waveforms, derive the dc equivalent voltage as a function of VM, E, and α,
where VM is the peak secondary voltage. The on-voltage across the SCR may be neglected.
• Next, derive the dc equivalent current (can’t use Ohm’s law directly, first get the voltage
across the resistor).
• For the given specs below, calculate the expected minimum and maximum firing angle, as
well as expected maximum and minimum output dc current.
The following values must be used for the analysis and iterative design of your battery charger:
• Rectified Peak Voltage: VM = 200V plus sum of last three digits of your student number.
• Battery Voltage: E = 100 V minus sum of last 2 digits of your student number (SN).
• Internal Resistance: RINT = 1 Ω plus one tenth of the last digit of your SN.
• Target Current: IDC = 2 A minus one tenth of the 2nd last digit of your SN.