ScottWang's Blog
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The symbols of Logic gates, OR, NOR, XOR, AND, NAND, Buffer, Inverter, Schmitt Trigger.
The symbols of L, C, R, Pot, Diode, Zener, Bjt, LED, Xtal, SCR, N, P MOSFET.
Zener Values
1W Standard VZ Tolerance is 5 %
3 . 3 V 1 N 4 7 2 8 A
3 . 6 V 1 N 4 7 2 9 A
3 . 9 V 1 N 4 7 3 0 A
4 . 3 V 1 N 4 7 3 1 A
4 . 7 V 1 N 4 7 3 2 A
5 . 1 V 1 N 4 7 3 3 A
5 . 6 V 1 N 4 7 3 4 A
6 . 2 V 1 N 4 7 3 5 A
6 . 8 V 1 N 4 7 3 6 A
7 . 5 V 1 N 4 7 3 7 A
8 . 2 V...
The MOSFET Specification :
2N5457-58D_Nch_Jfet.pdf
2N7000_7002_NDS7002A-Nch60V200mA_Vgs4V5-75mA_Vgs10V200mA_5Ω_fc.pdf
2N7000_Nch60V200mA_Vgs10V_5Ω_th2.1V.pdf
2SK1294_Nch_60V40A_50mΩ_Vgs=4V.pdf
2SK2842_Nch_500V12A_0.4Ω_Dc2Dc_Motor_Toshiba.pdf
2SK2843_Nch_600V10A_540mΩ_Dc2Dc_Motor_Toshiba.pdf...
The sound active control circuit -- Using the sound to active the relay to drive the load.
Mic → Pre amp → CR Differential circuit → Schmitt circuit → Rectifier and filter → Toggle flip flop → bjt and relay
R8 -- increasing the input resistance of Q2.
C4,R6 -- Limited the frequency of sound...
The below was what I designed for a detector of the input port of 40 pins connector, it can be expanded to more pins to detect that when you need more I/O ports.
The below was what I designed for a detector of an output port of 40 pins connector, it can be expanded to more pins to detect...
Input Protection for Vdd and Adc of uC.
If the Vdd of uC is 5V then the Zd1 and Zd2 are 5.1V, and R1 can be use as 0.22Ω/3W or 5W, if the Vdd of uC is 3.3V then the Zd1 and Zd2 are 3.6V, and R1 can be use as 0.1Ω/3W or 5W, the values of R1 will affecting the voltage of Vdd.
Two Sets of 10 channels O'scope and Multimeter Multi-Inputs Selector --
Two rails of O'scope can measure 20 points, or a single rail can measure 10 points and use another multimeter to measure 10 points.
O'scope And Multimeter Multi-Inputs Selectors :
This multi-inputs selector was designed...
1. Using a simple RC filter as resistor and capacitor for 5V and GND of uC surges and interference problems, processing the reference method, the R-value is according to the total current consumption of uC, when modifying the R-value still unable to achieve the desired effect, and then change...
1. NE555 Pulse Generator and PWM adjustable circuit.
D1, D2 : 1N4148.
Clock, t = 0.69((R1+VR1)*C1)+0.69((VR1+R2)*C1)
Pwm, Hi duty = 0.69((R1+VR1(①②))*C1)
Pwm, Lo duty = 0.69((VR1(②③)+R2)*C1)
The Circuit.
2. NE555 Variable Frequency Square Wave Generator.
If you only using square wave...
2 sets and 4 kinds ±5~15V fixed dual power supplies.
This is a two separated fixed positive and negative dual power supplies : this power has been used for over 18 years (before 1995)
Regulator IC : 7815, 7915, 712, 7912, 7809, 7909, 7805,7905.
Vout +15V, +12V, 10V, +9V, 0V, -9V, -10V, -12V...
The Transistor's Sink And Source.
If you want to know some more, google:
The Transistor's Sink And Source.
using transistor as switch.
using npn transistor as switch.
using pnp transistor as switch.
operational amplifiers tutorials.
Stepper Motor Forward And Reverse Testing circuit.
Using NE555,CD4017 and ULN2003 to build a stepper motor testing circuit with forward and reverse.
NE555 - astable circuit with adjustable frequency.
CD4017 - Decade Counter/Divider with 10 Decoded Outputs, using it to strobe the ULN2003...
The Internal Structure of NE555 and Application Circuits.
1Hz time base - using CD4060,CD4013, 32768 hz crystal.
I used this circuit for a long time.
The Equivalent Circuit of Zener diode Using Diode and LED Protection.
The circuits are using to explain for someone how a Zener diode work when using diodes, it's more easy to understand, and I hope these can help you some more.
