Clap switch/Sound-activated switch designed around op-amp, flip-flop and popular 555 IC. Switch avoids false triggering by using 2-clap sound. Clapping sound is received by a microphone, the microphone changes the sound wave to electrical wave which is further amplified by op-amp.
555 timer IC acts as mono-stable multi-vibrator then flip-flop changes the state of output relay on every two-clap sound. This can be used to turn ON/OFF lights and fans. Circuit activates upon two-clap sound and stays activated until another sound triggers the circuit.
Sound Activated Switch - [Link]
The Project works as electronic toggle switch. The circuit is based on CMOS CD4013 Flip Flop IC, The circuit has two stable states, ON and OFF. Once it is ON, it remains ON till you press the switch again. A short button press of a tactile switch SW1 latches the circuit ON and another toggles it back OFF. Relay switch contacts can handle high AC Voltage as well as High DC current, this makes the project suitable for application like ON/OFF Fan, Light, TV, Pump, DC Motor, any electronic project required electronic toggle operations and few other devices work on AC voltage up to 250V AC or DC current up to 5Amps.
Electronic Toggle Switch - [Link]
Dhananjay Gadre & Nidhi Sharma writes:
Microcontrollers, the heart of all modern electronic gadgets, are increasingly powered with sub-5V power supplies. This complicates the control of external loads powered by higher voltages. The reduced I/O supply voltage leads to increased complexity in handling high-side voltage switching. Figure 1 illustrates the conventional solution for controlling a 5V high-side switch, driven here by a 3.3V signal.
Zener level-shifter drives high-side switch - [Link]
by brmarcum @ instructables.com:
I hate Christmas tree lights.
Well not really, I just don’t enjoy having to climb under the tree every time I want to plug in or unplug the lights. In the interest of saving my sanity, I decided to build a motion activated switch that can power the lights for me. It has an integrated adjustable timer so they will stay on for as long or as short as I want. Here’s a video showing the final test on the fish tank light.
Motion Activated AC Switch - [Link]
App note from International Rectifier on their IR331x part which offers a bunch of power protection and control all in one chip. [via]
The new IR331x devices designed in P3 technology provide more accuracy of the current feedback. The IR331X devices suit for any application where the load current sensing is required. IR331X is fully protected: programmable current shutdown, over temperature shutdown and reverse battery protection. The current sensing features offer current readout accuracy, high frequency bandwidth, a versatile way to control the current shutdown and replaces the shunt resistor.
App note: Current sensing high side switch - [Link]
nevdull @ instructables.com writes:
Tactile switches (a specific type of momentary switch) are everywhere and they are especially popular on DIY electronics and microcontroller boards because they are well suited to act as a boot option or reset switch. Particularly, momentary switches are switches that don’t save their state when you depress the switch. That is, when you push the switch (and while you have the switch depressed) the circuit is ON, but once you let off the switch it reverts back to OFF.
Use a Momentary or Tactile Switch as a Pushbutton Switch - [Link]
by Claude Haridge:
Microcontroller-based products sometimes require rotary switches. As many microcontrollers have an onboard ADC, it is easy to replace the rotary switch with a low cost potentiometer, when a rotary switch is too expensive or unavailable.
Although digitizing a potentiometer setting to act like a switch requires only a few instructions, an immediate problem is that instabilities in value occur at the switching threshold between one value and the next due to electrical or mechanical noise. The solution is to introduce upper and lower hysteresis thresholds about each transition so that the potentiometer needs to move beyond a threshold before another switch state is validated. For every updated switch state, another pair of thresholds replaces the previous. In this manner, the hysteresis provides clean switching between states.
Replace a rotary switch with a potentiometer - [Link]
by Viktor Safronov:
Sometimes you may need a group of switches where, if any switch is activated, it deactivates the previously active switch. This Design Idea implements such a function with relays.
This “one and only one” function is often implemented as mechanical switches in which an actuator (usually a movable metal bracket) is used to switch contact groups on and off. When any switch is pressed, this bracket first deactivates all switches, then activates the pressed switch.
Exclusively select 1 of N relays - [Link]
The era of the MEMS switch may finally be here thanks to the research efforts of GE. Its MEMS chip, as small as 50 microns square, swathes as fast as 3 GHz and can handle up to 5-kiloWatts of power, making it a candidate for everything from industrial power control, to turning on light bulbs to switching antennas inside a smartphone.
MEMS Switch from GE claims fastest/highest Power Crown - [Link]
Do you have an application where a black switch is not suitable? We have an elegant white one for you.
Rocker switches are available in a vast majority in a black version. When we take a look at catalogues of renowned producers we´ll usually find there mainly black types and only a few white ones. However a switch in a black version can be advantageous in many applications like office devices, PC, “white” (home) goods, lighting, equipment, but also in many other devices having enclosure other than black, or where just a white version can be an interesting design element. Even in our electronic branch it´s particularly true, that a “package sells” and an aesthetic design of a device can be one of the factors of a market success.That´s why you can find in our stock two novelties – a white rocker switch 1832.3311 ((DPST, 20A/250VAC) as well as a round 1881.1105 (SPST, 12A/250VAC). Both novelties belong to well proven series with widely known properties. Detailed description can be found in 1830 and 1881 series datasheets.
Recently we added into our standard stock offer also many other types from Marquardt and you can find them below this article.
Black or white? - [Link]