1. Lab #4 – Transistor Switching Circuits

2. © Bob York Back to TOC Capacitive Loads +5 V V in 2N3904 2N3906 V out 0.1 μF 10 kΩ V DD V in V out 0.1 μF IoIo V out C C R V DD V out I c +5 V 2N3904 0 V 5 V V in 1 kΩ 100 kΩ 0.1 μF 2N3904

3. © Bob York Back to TOC Risetime 10% 90% V max 10-90% risetime

4. © Bob York Back to TOC LC Load +5 V V in 0 V 5 V V out 2N7000 3.3 kΩ 10 kΩ 470 Ω 100 μH 0.1 μF 2N7000

5. © Bob York Back to TOC S-domain Analysis V DD V out L t = 0 C R V out sL 1/sC R on V DD V out L C R R V DD /s V DD V out L t = 0 C R V out sL 1/sC R on V DD V out L C R R on V DD /s

6. © Bob York Back to TOC DC Fan and Driver DC Brushless Fan 12VDC Dimensions: 1.60"W x 1.60"H x 0.40"D 6.7CFM Ball Current: 100mA Power: 1.2 watts Agency approvals: UL/CUL/TUV/CE Noise: 25dBA Connection: 10" W/Connectors FAN,12VDC,6.7CFM,1.6"SQ X.40" BALL,10" LEADS, UL/CUL/CE Jameco P/N 290010PS Mfg ADDA INC Mfg # ADO412HB-G70 RoHS? No In Stock Yes Voltage (VDC)12 Size (W x H x D) (inches) 1.60 x 1.60 x 0.40 Air Flow (CFM)6.7 Bearing TypeBall Current (mA)100 Power (Watts)1.2 Noise (dBA)25 Connection (Leads)10 Agency ApprovalsUL/CUL/TUV/CE +12 V V in 2N7000 DC motor/fan M 0.1 μF

7. © Bob York Back to TOC Inductive Spiking +5 V V in 0 V 5 V V out 2N7000 10 Ω 100 μH 100 Ω f = 100 kHz 2N7000 0.1 μF +5 V V in 0 V 5 V V out 2N7000 10 Ω 100 μH This circuit gives a nice demonstration of ringing for a 2kHz input

8. © Bob York Back to TOC Boost Converter +5 V V in 0 V 5 V V out 2N7000 22 Ω 100 μH 100 kΩ 10 μF RLRL 2N7000