partner: LM317-dat
Boards
Function
The NE555 timer IC can generate:
- Delays (timing circuits)
- Square waves (oscillators)
- PWM signals
- One-shot pulses (monostable mode)
It operates in three modes:
| Mode | Use Case | Description |
|---|---|---|
| Monostable | One-shot pulse | Output goes high for a fixed time after trigger |
| Astable | Oscillator | Continuously generates square wave pulses |
| Bistable | Flip-flop | Toggles output on each trigger |
info
+---+--+---+
1 | GND VCC | 8
2 | TRIG DIS | 7
3 | OUT THR | 6
4 | RESET CTRL | 5
+----------+
| Pin | Name | Function |
|---|---|---|
| 1 | GND | Ground (0V) |
| 2 | TRIG | Trigger input (active low) |
| 3 | OUT | Output |
| 4 | RESET | Reset (active low, connect to VCC) |
| 5 | CTRL | Control voltage (optional, add 0.01µF cap to GND) |
| 6 | THR | Threshold (used in timing) |
| 7 | DIS | Discharge (used in timing) |
| 8 | VCC | Power (4.5V to 15V) |
- input voltage up to 12 (16)V
datasheet == https://www.ti.com/lit/ds/symlink/ne555.pdf
T = 1.1C = 1.1 * 500 000 * 0.000047 = 25.85 seconds
⚙️ Mode 3: Bistable (Flip-Flop)
🔁 Toggle output on/off with triggers
🔧 Basic Wiring:
- Trigger button to Pin 2
- Reset button to Pin 4
- Output toggles high/low
⚡ Applications
| Application | Example Use |
|---|---|
| Timer | Delay off circuits |
| Oscillator | LED flasher, tone generator |
| Pulse Width Modulation (PWM) | Brightness/motor speed control |
| Bistable Switch | Toggle button circuit |
| Frequency Generator | Clock signals for logic circuits |
📘 Example: LED Flasher Circuit (Astable Mode)
VCC (+)
|
[R1]
|
+-------+
| |
[R2] Pin 7
| |
[C1] |
| |
GND Pin 6
|
Pin 2
|
GND
Pin 3 (OUT) → LED + resistor → GND
tuning pulse
used on board SCU1063-dat
output control by D4184-dat mosfet-dat