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

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1answer
59 views

Is there any notification system that can turn on a LED pulse?

I have an idea, and I searched if it exists and didn't find anything. I'm a live sound Engineer, and many times my musicians want to call for my attention, and I'm distracted with other sound things. ...
0
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1answer
50 views

What is the type of device that will switch to battery when the regular power supply is cut off? [on hold]

Just need a device we can buy and include in circuit. Like if we are running a device with 12V from P.S, and that cuts off, it switches to battery.
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2answers
54 views

Controlling AC mains using Arduino and removing control easily

I am planning to for an Arduino to read status of a switch, and accordingly switch on and off AC appliance, for a demo purpose. I want to add a feature to it of easy recovery to manual switch control. ...
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0answers
37 views

Slewing sensor across entire 5V input signal using potentiometers

I am trying to slew a vacuum sensor in my car. My trouble is, use of a single potentiometer only allows for slewing of the lower range of the input signal, that is, from 0 - 100%, the signal can only ...
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2answers
53 views

Designing an ABBA circuit (3 input, 2 output) inputs: (GND, +V, Logic)

I'm working on a relatively simple Arduino project and want to reach an elegant solution for a circuit. I'm not sure if there is an existing IC for what I want to do, but here is a diagram for what ...
0
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1answer
28 views

Fastest resistive touch panel response time?

1/ What is the fastest response time of touch panel? 2/ It seems resistive panel can get under 10ms, but I want a faster panel, is there any one with under 1ms or microsecond response time? 3/ Why ...
3
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3answers
423 views

Automatically switching from 9V battery to DC wall adapter on insertion

I have a simple circuit that runs off of a 9V battery. I'm re-designing it so that it can also run off of an external 12V DC source (ie: a wall adapter). I want to design the circuit so that if both ...
0
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1answer
48 views

Adjustable charge current from programming resistor for Li-Ion charger - how to change on demand?

I am designing a device which has an integrated Li-Ion battery (single cell, for simple low power portable digital device) and normally charges by way of a buck converter which goes from 12-16V ...
2
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2answers
45 views

Protecting a comparator in a tension measurement device

I am building a device to measure the tension of a conducting wire using an Arduino. The basic circuit concept consists of two stages: The wire is placed in a strong magnetic field. Then the ...
0
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1answer
63 views

How does this PMOS circuit work?

I've been trying to figure out how this PMOS circuit is functioning. B_VCC is 5V coming from a USB port on the board, while VCC5V is used elsewhere in a regulator to create 3.3V but otherwise does ...
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1answer
57 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
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2answers
106 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
33 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
90 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
49 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 ...
15
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3answers
589 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
124 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 ...
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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?
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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
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1answer
63 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
50 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.
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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
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3answers
221 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..
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2answers
96 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
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1answer
95 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 ...
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4answers
155 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 ...
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3answers
55 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 ...
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3answers
134 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 ...
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2answers
59 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. ...
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3answers
100 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. ...
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4answers
214 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.
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2answers
211 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 ...
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2answers
102 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 ...
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3answers
72 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 ...
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1answer
83 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
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1answer
85 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
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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 ...
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2answers
96 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
171 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
64 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
76 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
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1answer
89 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
74 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
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3answers
48 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
79 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
40 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 ...
1
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1answer
61 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 ...