Devices to interrupt or route a signal or power one of several ways.

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1answer
42 views

Switch shift by voltage

At \$t=0\$ switch A opens, switch B closes when there is a voltage, U2. U is a DC voltage source \$> 0 \$ also is the circuit until \$t = 0 \$ in stationary state. My question is whether switch B ...
3
votes
2answers
101 views

Switch on computer with microcontroller

I'm making a simple microcontroller based circuit to turn on a computer when certain events are triggered. I am interfacing it using the PCs soft power switch pins on the front panel header: There ...
0
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1answer
28 views

Quick-connect terminals - how to mount/connect them? Or Alternative PCB switches

I am currently designing a product for use in the automotive industry, and it will be used externally to the vehicle. I am at the awkward stage of trying to combine PCB design with product ...
0
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1answer
35 views

Help me about system switch control ladder light? [duplicate]

We all know about the system of two switches controlling one lamp(at the ladder) like the picture. Could you help me design a system of four switch to control one lamp ? thanks
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1answer
83 views

How Start/Stop Push Button Switches work?

how exactly this switch works? does it close the contacts when green is pushed and keeps it closed until red is pushed?
2
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3answers
47 views

Magnetic reed switch current ratings

I wish to use some 12 V, 5 W xenon light bulbs under separate shelves of a cabinet. I'd like them to power-on using a magnetic reed switch attached to the cabinet door. The magnetic reed switch I ...
13
votes
1answer
522 views

What does a “sad face with a bow tie” represent?

Some trains in the Madrid metro network have small metal boxes with this sign on them: There are no other signs on the box and some signs only have the "bow tie". I'm guessing it's two Zener ...
2
votes
3answers
113 views

How do Wi-Fi controlled light switches feed themselves?

There are smart light switches in the market that are Wi-Fi controlled like Plumlife (formerly ube) and Belkin WeMo. I wonder how they control the electricity that they operate on. When I unplug my ...
0
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0answers
35 views

Could you explain me how the Proximity Switches of the elevator work?

Could you explain me how the Proximity Switches of the elevator work?
1
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1answer
42 views

How do these switches work?

I have these switches in my home which you push once, they don't flip over just go back to the initial position. We have like 4 of those and I really want to know how they work. Can someone explain ...
0
votes
1answer
59 views

Adding a switch to an existing light

I've read about 3-way and 4-way switches but I don't understand something. I am aiming to create a bluetooth controlled home network. One of the modules would include a light switch. How would I go ...
0
votes
2answers
48 views

What is the function of switches in optical panel encoders?

I want to use optical encoder in my design. In the datasheet of the optical encoder, pin2 and pin3 are used as switches. Could you please explain how these switches work and how to use them? Thanks.
1
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0answers
27 views

Lighting in the hall: How to substitute a missing wire? [migrated]

I have a problem with the lights in my appartement. The current setup is below (and photos further down): simulate this circuit – Schematic created using CircuitLab There are two ...
2
votes
3answers
217 views

Clap Clap Switch Modifications

I wanted to make a modification to the clap clap switch with a schematic diagram below but instead of a LED lighting I want to make it turn on a small fan..
1
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2answers
89 views

Switching an LM317BTG on/off using a microcontroller

We're using an LM317BTG to power a 4V modem (the LM is connected to a 12V battery). The modem can produce peak currents of up to 2A during transmission bursts. Under normal operations, the modem ...
0
votes
1answer
85 views

Calculate current using compensation

simulate this circuit – Schematic created using CircuitLab Okay, first I'd like to apologize if this question seems stupid, but I'm preparing for an exam, and don't know how to solve this ...
0
votes
4answers
154 views

Computer controlled rotary switch

I have a circuit with a rotary switch (1 pole, 6 positions). Instead of turning this switch by hand, I would like to control it via a computer. Are there any components that can do this? They would ...
0
votes
3answers
54 views

Turn a load on with a pulse of power, keep on until (NO) button is pressed

I have a device that sends a pulse +12V when access is confirmed. I would like to keep a relay live until a button is pressed to close the circuit. This is used to start up a cars (acc) and allow it ...
0
votes
3answers
133 views

Using an SPST knife switch to power on/off a PC

The title is it in a nutshell I've got an antique knife switch that I'd like to use to power up (and down) an embedded PC. The PC power switch is essentially two wires, a ground and +5v (measured ...
0
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2answers
57 views

Best place for a switch when using an always connected power adapter

I recently bought this: http://smile.amazon.com/gp/product/B00II1MN5I and am planning on using it for under cabinet lighting in the kitchen. ...
1
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3answers
84 views

Determine break in long circuit

I have a circuit of switches like this. The switches are a long way from the supply and a long way from each other. ...
0
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3answers
167 views

How do I get a digital signal from a switch?

I want to essentially drive a relay using a switch. For eg: If the switch (AC Voltage : 220v, 50Hz) is switched on, it sends a digital signal to the relay to switch off.
1
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2answers
164 views

limit switches to control motor direction

I am trying to use two limit switches and two DPDT relays to control the direction of the motor. When the power is applied the motor should rotate one direction (direction for this question isn't ...
1
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2answers
100 views

Bidirectional solid state switch for solenoid

I'm building a circuit to control a flip dot display, which is basically a matrix of solenoids which you control with bidirectional current across the 25 columns and 7 rows of the board. The ...
0
votes
3answers
70 views

Switch between two digital signals with no microcontroller

I'd like to use an Arduino to send wirelessy (RF 433MHz, probably) two different digital signals to pilot two different relays (later they will be much more). I know probably this is something very ...
0
votes
1answer
78 views

How can I amplify cellphone's vibrator signal to switch my home electricity on or off?

I need to connect my Samsung s1 cellphone to my home's lights when I am away. I realised that I can use my cellphones' vibrator signal when I call my "Home" cellphone number. I know that the mentioned ...
0
votes
1answer
81 views

What is a 'normal' resistance level for a closed switch?

In a closed contact or a closed switch, theoretically, the resistance should be zero, but in actual measurements the resistance is very close to zero but not zero. So my question is: What is a ...
0
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0answers
25 views

TILT Sensors vibration test

I have to install a tilt sensor in an enviroment with a lot of vibrations. In a device installed in a truck. I want to know what is the vibration limit before we get a false read. I would work with ...
0
votes
1answer
35 views

Current Injection Via Jumper Design Help

I am currently designing a circuit that uses a 5V 2A power brick. The circuit requires a current source and I have seen good efficiency with Ohm's Law. The current is variable through a 2k ...
0
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2answers
95 views

Identifying open switches in a serial circuit

I have an equipment that includes a circuit made of a bunch of NO switches arranged in serial. This circuit includes a LED that turns on when all the switches are closed. When one or more switches are ...
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1answer
156 views

Why is the LED of my Illuminated rocker switch always on?

I recently purchased a rocker power switch from RadioShack (103-R13-135B-02R-EV) and it works great. However, even when the switch is off, the small red LED stays on. Is this normal? Won't this ...
1
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4answers
60 views

GPS Antenna Selector: How to electronically select one antenna from multiple available antennas?

I want to connect multiple GPS antennas to a single GPS module and select one of them based on some logic. Basically, I want the module to receive signals from only the selected antenna. Is there an ...
1
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2answers
72 views

Actuating a relay (either 5V or 12V) with 3V

I am trying to figure out how I can actuate a high amperage 12V relay with only the batteries I have on board. Basically the idea is here to have a 3.7V lithium cell, a momentary switch to actuate ...
0
votes
1answer
79 views

Solid State Relay Capacitance Bad for Audio?

Regarding MOSFET optocoupler relays like the Panasonic AQW212, am I correct in understanding that the capcitance between the terminals and ground when the switch is open ("off") is around 100pF when ...
0
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0answers
34 views

Bypass switch for amp

I've just successfully completed a CMOY amp and I'm pleased with the result. However, I want to be able to hear the difference between the original signal and the amplified signal, so I put a switch ...
2
votes
1answer
72 views

Toggle battery powered LEDs

I am helping to build a costume prop that has four LEDs lights on it (1 white and 3 amber). This device is worn on the wrist, so space for power is limited- a 9V battery or something that will fit in ...
0
votes
3answers
46 views

Identification of switch type casing type or housing type

I don't know what or how to identify this switch. Its dimensions are: 29.5mm by 25 by 21.5 tall. It has a lug for a screw on the side you can't see it is actuated by a pin on a separate housing ...
0
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1answer
61 views

Switching power between two 7-segment displays using NPN transistors

So, I am working on a small project and forgot to order PNP transistors to switch the power to two common-anode 7-segment displays. Like this, for example: All I have in hand at the moment is a ...
0
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1answer
39 views

Remote Wireless 4CH Switch On/Off - Data PIN Network Cable

Planning Stage I'm in the planning stages of making a wireless on/off switch that will basically cut off pin 6 on a network cable. I know little about electronics and I've attempted to learn as much ...
0
votes
1answer
49 views

Unexpected results in Multisim

I am in the process of selecting a N channel MOSFET for switching purposes and thus, tried out this simple circuit in Multisim. But it seems that the MOSFET conducts in the cut off mode and remains ...
1
vote
2answers
185 views

Power switch with slow control signal

I am trying to switch on and off a circuit that draws about 0.8 amp at 12 V. The obvious choice is to set a MOSFET. The problem is that the control signal (the one that goes on the gate of the MOSFET) ...
0
votes
1answer
80 views

Laser activated switch using a photo-transistor

I would like to make a laser activated switch using a photo-transistor or an LDR, by which I can switch off the lights in a room from a long distance. I just have to point the laser and it will detect ...
1
vote
1answer
153 views

Bidirectional AC Switch with IGBTs

I came across a "IGBT Bi-directional Switch" on the web while looking for a solution to my problem of protecting a TRIAC/SSR from a short-circuit. Since TRIAC/SSR turn-off is not in my control, I'm ...
0
votes
2answers
100 views

MOSFETs connected in series forming an H-bridge circuit for switching

I want to develop an H-bridge circuit using 2 MOSFET switches connected such that when the switch 1 is on (switch 2 off) the output voltage should be +5V and when the switch 2 on (switch 1 off) the ...
1
vote
1answer
48 views

Switch OFF-(ON)

Easy question here. I'm designing a circuit which needs a switch for the main power supply. I would like a switch that keep the power OFF normally and the power ON while holding the push switch. Is ...
0
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2answers
68 views

Control automotive AC switch via TPS voltage

The A/C compressor is engaged via a single wire that comes from the 'A/C' button on the dash board. I want the A/C button to disengage when the throttle is at 50%. The throttle position sensor (TPS) ...
2
votes
1answer
152 views

What is the simplest analog circuit for integer addition modular 2?

This probably is a rudimentary question. I would like to have a simple analog (switch) circuit for addition modular 2, or \$a_1+a_2+\cdots +a_n \$ (mod 2). Certainly, digital transistors can ...
0
votes
1answer
47 views

Electrical circuit for detecting and charging a battery at 12 v

I have an input source of 12 v at 6 amp. How can I use a toggle switch or a circuit that can detect if the source is active, it should let the voltage pass if present otherwise not. Also what is the ...
0
votes
2answers
51 views

Switch PCIe connections

I'm trying to implement a PCI express switch; one lane from SoC and, two for mini PCIe ports. Something like the picture below. But I'm confused with the Tx and Rx connections, the transmitter ...
0
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2answers
53 views

Linear actuator power supply and remote or switch

This will be my first DIY project involving electricity so I want to make sure I buy the correct components. I'm purchasing a used telescoping column (aluminum and steel, 4000n) that has two actuators ...