Schematic of emulator
D4
C3
Q1
V1
C1
Capacitance
100uF
R1
Resistance
100 Ω
R3
Resistance
100kΩ
R4
Resistance
500 Ω
K1
D3
R2
Resistance
1000 Ω
R5
Resistance
500 Ω
U1
D2