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

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2
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1answer
54 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
0answers
57 views

Inexpensive rotary switch [on hold]

I'm working on a design and I want to include two simple rotary style switches. One for on/off that needs to handle 5V at 1 Amp, and another that is just for selecting one of two options for the ...
0
votes
3answers
29 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
33 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
votes
1answer
23 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
33 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
167 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
42 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 ...
0
votes
1answer
45 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
71 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
43 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
votes
2answers
29 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
146 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
28 views

Electrical circuit for detecting and chargine battery at 12 v

I have input source of 12 v and 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 otherwise not. Also whats the best way to ...
0
votes
2answers
35 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
votes
2answers
29 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 ...
2
votes
1answer
73 views

Device to switch a 220VAC/40A resistive load

I need to switch a 220VAC/40A resistive load. I only need on/off switching, no phase control. I would like to avoid mechanical (moving parts) components if at all possible because of reliability ...
2
votes
3answers
91 views

Switch power supply/battery

I have a power supply of 5v DC 5Ah and a 12v 2Ah lead battery. I was thinking to make a circuit to switch battery line when power is off. I made a little schema, what i'd have to put instead of switch ...
1
vote
1answer
100 views

Push Button ON-OFF Five seconds

I have to design a power supply with the LTC1707. It have a enable input to control it. Now I have to enable an disable this switching supply with a push button. Only when I push in button during ...
0
votes
1answer
64 views

Best way to emulate network switching on PCB

I'm interested in wiring up some Raspberry Pi Compute Modules together on a custom PCB board with DDR2 SODIMM connector interfaces. ...
2
votes
2answers
135 views

What is the difference between 4-leg and 2-leg momentary tactile switch? [duplicate]

After many search, I don't know still that what is exactly the difference between 4-leg and 2-leg momentary tactile switch? 4-leg: 2-leg: Why do they use 4-leg in many cases? for example, ...
2
votes
3answers
74 views

Is there an IC with a series of 2-input switches that can have all elements switch with one signal?

I want to select either input A's 4 signals, or input B's 4 signals. So I'm more interested in using 3-pin like switch, that can short circuit from the either A or B (not open or close one input) Is ...
0
votes
3answers
61 views

How should a SPDT switch be wired for a digital input?

I want to connect a switch to a digital input on a logic board and make it so that the input goes high when the switch is pressed. I'll be using a SPDT switch: Should I connect the digital input to ...
1
vote
1answer
66 views

How to make a simple Video Switch?

I thought making this would be simple, but I've found it a lot harder than I anticipated! What I mean is that I have one screen/monitor, and two video players (all video is through RGB component, RCA ...
0
votes
2answers
126 views

Transistor as switch between similar voltages

I want to use an XBee to relay data coming from a serial device. The XBee will be sleeping most of the time; waking at regular intervals, powering on the serial device, relaying the serial signals, ...
0
votes
1answer
48 views

Electronic selector / gate

The circuit that I am looking for is supposed to work as follows: The circuit has, besides power, three inputs, and two outputs. The circuit is supposed to act like a get, and let an analog signal ...
3
votes
3answers
320 views

Is a protection diode needed for a resistive load?

In some applications a flyback diode is added parallel to the load. Is that because the switching causes reverse voltage for inductive loads? What if we have a resistive load instead? Do we still need ...
2
votes
2answers
58 views

Read Switch Status without interfering with LED

I'm a software guy trying to get my head around how to measure the status of a switch connected to a LED as shown below through a digital input of a MCU. My first try was many variations of ...
0
votes
1answer
88 views

Two circuits with different voltages - should I use a transistor or an optocoupler as a switch

I am doing a project using the output of a Raspberry Pi GPIO pin (3.3V) to power a 12V remote control. If the two are on different circuits, can I use a transistor to switch on the 12V circuit or do ...
0
votes
1answer
48 views

Covering exposed contacts on a toggle switch

I need to mount a mini toggle or rocker switch to the outside surface of a box. For various reasons I cannot drill a hole, so the entire switch needs to be freestanding or glued to the surface. (There ...
0
votes
2answers
61 views

Alternatives to relay/contactors in DC circuits

I wanted to switch a 60Vdc line to ON/OFF using a 60Vdc controlling signal for some kind of a feedback system (yes both are 60Vdc). Presently I have two options visible: Solid State 60Vdc input ...
4
votes
3answers
450 views

Understanding a circuit for reading current passing through human bodies

I found on Instructables this circuit that is used to detect when two conductive pads are touched at the same time by a person (or, in that particular example, a chain of people). Used in ...
0
votes
2answers
97 views

How to use a 10 pin dip switch on a 8x3 Encoder (IC 74LS148)?

I've been trying to get an 8x3 encoder (IC 74LS148) working using a 10 pin dip switch, I simply connect the 1-7 ON sides of the switch as inputs for the encoder and the OFF sides of the switch to the ...
0
votes
1answer
63 views

7 Segment display binary to decimal

I have a few questions about 7-segment LED displays. When we build a circuit using 7 segment (common-anode) and decoder (7447), we also use 4 tactile switches to make combinations. Should I directly ...
2
votes
2answers
111 views

Better way to drive higher voltages

In order to drive pass transistors (MOSFETs) located between two non-zero voltage points, one can use a resistor divider followed by a MOSFET as seen here where V2 is high enough to drive the top ...
0
votes
1answer
40 views

Automaticaly switch on/off an (APC) UPS

I need to switch on my APC UPS at 2 AM and switch it off at 8 AM every day. Would like to switch on/off the mains power to the UPS too. I am not an electronics guy, but started to learn and have ...
1
vote
5answers
178 views

Emulating a switch with open drain outputs

I need to replace mechanical switches with some kind of digital switch. Specifically I want to sent control inputs to various arcade games that use standard JAMMA inputs, which are basically switches ...
5
votes
4answers
820 views

When to use pull-down vs. pull-up resistors

After learning and experimenting with microcontrollers, the concept of pull-up- and pull-down resistors has been understood and saved to my hard drive. I now understand when and how to use them, and ...
0
votes
1answer
81 views

Connecting ON/OFF switch

Forgive me for the simplicity of this question but I am a microelectronics/very low voltage guy, and I have only 1 switch so I want to get it right the first time. Better safe than sorry :) I have an ...
1
vote
0answers
51 views

Rechargeable battery with a photovoltaic switch

I did some searching around on the forum but with absolutely no electrical background, I have exhausted my searching and hope I can explain my issue. What am I trying to do? I have a solar panel and ...
-1
votes
1answer
73 views

replacing DIP switch with Analog Switch

In order to minimize the number of components for measuring different types of signals(Resistance, Voltage, Current, ETC), I have designed circuit using DIP switch which the user can turn on and off ...
1
vote
1answer
94 views

Are selected values for R1 and C1 reasonable?

Can anybody help with the circuit and specifically the selection of values for \$R_1\$ and \$C_1\$? I tried to create a p-channel based MOSFET 1A switch for MCU based upon OnSemi AND9093 Using ...
0
votes
1answer
52 views

RC Schmitt Trigger Debouncing - Cap discharged but there is a voltage across it still

As you can see in the image, I'm running the example given in here where I would debounce the limit switch. I'm running the SN7414 with the given resistors in the diagram. The problem here is that ...
0
votes
0answers
45 views

Mono-stable trigger circuit (monoflop) with start delay

I'm sorry if this question is a duplicate, but I'm not sure about the right terminology (in english) about my problem. I've got a device which operates at 13.5V. I want to switch this device with a ...
0
votes
3answers
108 views

Is there a type of Switch that is open until Armed?

I'm designing a circuit that will need to be off until the user decides to 'arm' the circuit. It should then always be closed (and hard to hack into the on position). Does a certain component exist ...
2
votes
2answers
88 views

How to completely turn off device when float switch is open

Background Below is the circuit I designed to open a solenoid valve after a delay from C2 (represented by L1). S1 is a float switch which closes when a resevoir goes below a given level. The reason ...
0
votes
1answer
73 views

Separated powers and high power switches? Alternatives to relais?

I want to use an Arduino (5V, 0-40 milliamps) to control some switches, which in turn control a high current line (12V, 40A). But the relays which I use use too heavy coils for the Arduino to pull ...
-2
votes
1answer
68 views

Switch diagram, do not know what it means, or what it represents [closed]

A neighbour asked me if I knew what these electrical switch symbols meant, or at least what they were so he could find out more:
0
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3answers
101 views

How to turn on/off a sub circuit with a transistor

I bought a dtc144 transistor because it was written in its datasheet that it could do a "Switching circuit" ( as it is written in the Applications section in the datasheet). I though it meant that I ...
1
vote
2answers
72 views

Trigger led with both Arduino and tactile button

I want to trigger a LED with both an Arduino and a hardware switch without coding any button logic in the Arduino. simulate this circuit – Schematic created using CircuitLab When the ...