Summary of NEVER FORGET TO TURN ON THE COOKER HOOD AGAIN
This article describes Peter's project to automate a cooker hood using an Arduino. The system detects stove usage via a current transformer on the 3-phase line, buffers the signal with an op-amp due to high impedance, and triggers relays to power the hood automatically. This ensures fumes are removed even if the user forgets to switch it on manually.
Parts used in the Automatic Cooker Hood Switch:
- Arduino microcontroller
- Current transformer
- Shunt resistor
- Op-amp buffer
- Relays (pair)
- Cooker hood
- 3-phase stove power line
The cooker hood is a wonderful invention for removing excess fumes and steam from the kitchen. But like all electrically-powered devices, it only works when it is turned on. This was the problem facing [Peter], whose family are enthusiastic cooks who frequently forget to hit that switch. His solution? An automatic cooker hood switch that comes on when the cooker is in use, and stays on long enough afterwards to fully dissipate the fumes.
At its heart is a current transformer on the 3-phase stove power line, and we’re treated to a lesson in reading from these devices with an Arduino. They have a shunt resistor across which to produce a voltage, and their AC output is placed upon a reference DC voltage to supply the microcontroller pin. The impedance is quite high, so when the sensor had to be placed a distance from the microcontroller it necessitated an op-amp buffer. The readings then cause the Arduino to trigger a pair of relays to switch on or off the cooker hood. We can imagine that the family kitchen is thus a much pleasanter environment for it.
Cookers can also provide quite a hazard when they are left on. To that end, we’ve also featured a cooker alarm in the past.
Source: NEVER FORGET TO TURN ON THE COOKER HOOD AGAIN
- How does the automatic cooker hood switch detect when the stove is in use?
A current transformer on the 3-phase stove power line detects the activity. - What component produces a voltage across which the AC output is placed?
A shunt resistor is used to produce a voltage for the sensor readings. - Why was an op-amp buffer necessary in this circuit design?
The high impedance of the sensor required an op-amp buffer when placed at a distance from the microcontroller. - Can the Arduino trigger multiple devices simultaneously?
Yes, the readings cause the Arduino to trigger a pair of relays to switch on or off the cooker hood. - Does the cooker hood stay on indefinitely once triggered?
No, it stays on long enough afterwards to fully dissipate the fumes before turning off. - What problem did Peter solve with this invention?
Peter solved the issue of his family forgetting to turn on the cooker hood while cooking. - Is there a risk associated with leaving cookers unattended according to the text?
Yes, cookers can provide quite a hazard when they are left on.
