NE555 delay switch module (12 V): specs and pinout
A 12 V time-delay switch module sold with NE555 in the name. This page gives the NE555 timer chip facts only; the module's actual delay range, switching element and load rating are not covered by an official document.
Specs
| Spec | Value | Source |
|---|---|---|
| Chip supply voltage | NE555: 4.5 V to 16 V | source Section 5.3 Recommended Operating Conditions |
| Chip output current | Output can sink or source up to 200 mA | source Features p.1; Section 5.3 |
| Chip operating temperature | NE555: 0 C to 70 C | source Section 5.3 |
| Monostable pulse width | tw = 1.1 x RA x C approximately; minimum pulse width 10 us | source Section 6.3.1 Monostable Operation |
| Trigger and threshold levels | Trigger about 1/3 and threshold about 2/3 of the supply voltage | source Description, p.1 |
| Timing vs supply | Pulse duration is independent of supply voltage if the supply is constant during the interval | source Section 6.3.1 |
Power
| Value | Source | |
|---|---|---|
| Supply | Chip: 4.5 V to 16 V; module rated 12 V by title | source Section 5.3 |
Chip pins
These are the pins of the chip on the module, from the chip datasheet. The module's own header may label or expose them differently.
Rows are the NE555 8-pin package pins (D/P packages). The module board's terminals, trimmer, delay mode and output switch are not covered by an official document.
| Pin | Function | Voltage | Notes | Source |
|---|---|---|---|---|
| 1 GND | Ground | 0 V | source Section 4 Table 4-1 | |
| 2 TRIG | Start of timing input; TRIG below 1/3 of CONT voltage sets output high | source Section 4 Table 4-1 | ||
| 3 OUT | High current timer output | source Section 4 Table 4-1 | ||
| 4 RESET | Active low reset input | source Section 4 Table 4-1 | ||
| 5 CONT | Controls comparator thresholds; outputs 2/3 VCC | source Section 4 Table 4-1 | ||
| 6 THRES | End of timing input | source Section 4 Table 4-1 | ||
| 7 DISCH | Open collector output to discharge timing capacitor | source Section 4 Table 4-1 | ||
| 8 VCC | Input supply voltage | 4.5 V to 16 V | source Section 4 Table 4-1 |
Build with it
Project ideas for the NE555 delay switch module (12 V). Each link opens Soldr with the prompt filled in; Soldr assigns the pins, checks power and shows how to wire every part.
- Delay-off light for a 12 V strip: The module's trigger input, delay mode and output switch are not documented, so how it is started and what it switches must be read from its printed labels first. Do not exceed the module's printed output rating with the strip's current. Learning project.
- Timed fan run-on: The fan's current is on its label; compare it with the module's printed load rating and do not exceed it. Learning project.
- A delay timing check that measures how long a 12 V delay module output stays on, with a multimeter and a 12 V adapter: No load is connected. The module's delay range and trimmer are not documented, so time the output with a meter and a stopwatch and compare with the chip's tw = 1.1 x RA x C only if the timing resistor and capacitor values can be read from the board. Learning project.
Common mistakes
- The chip sheet limits the NE555 supply to 16 V; the module's own protection, load rating and behaviour on vehicle supply transients (well above 16 V) are not documented, so use a bench 12 V supply, not a vehicle, and check the printed rating (source: link, Section 5.3).
- In monostable mode TRIG must be high for at least 10 us before the end of the interval or the output stays on; a held-low trigger input keeps the output on (source: link, Section 6.3.1).
- A chip output rating of 200 mA is not a relay or lamp rating; check what the module's output stage can switch (source: link, Section 5.3).
Not covered by the official source
- No document covers the module; delay range, trigger input type, output switch and load rating are not given.
- The relay module's control input is not documented, so no pairing with a relay module is suggested.
Sources
- link (TI NA555/NE555/SA555/SE555 data sheet SLFS022K, March 2026)