# Tag Info

1 vote

### Cycle off a voltage at a specific amplitude height [revised]

You could detect a change in direction of the input sinusoid, using a differentiator. The derivative of $sin(x)$ is zero when it changes direction, at its peak and valley points, and it becomes ...
• 42.2k
1 vote

### Using one momentary switch for multiple IC's at different pull-up voltage levels

I strongly suggest that you consider adding full isolation circuitry in the form of A / B selection analogue mux switches so that the particular switches that you want to assign dual mode ...
• 57.6k
Accepted

### Using ON-ON switch instead of ON-OFF switch?

An ordinary ON-OFF switch (known as a single-pole single-throw, or SPST) has two terminals. Call them A and B. In one position A is connected to B; in the other position there's no connection between ...
• 1,535
Accepted

### What is the purpose of R1, D1 in this gate driver? How they can control the turn on/off time?

R1 is there to control the turn ON time of the FET. This could be because of EMC issues if you have too abrupt current spikes or simply to limit the inrush peak current. The diode is there to ...
• 424
1 vote
Accepted

### Add Raspberry Pi GPIO to existing 12V application

There are several ways to approach this. The most straightforward is to find some DC supply that is always present when your "device" is powered. Then connect your R1 to that rather than the ...
1 vote

### DY-SV5W Voice Playback Module

Pulling down two lines with one button will require some diodes. simulate this circuit – Schematic created using CircuitLab When drawn as a square matrix like this, you can see that you can ...
• 176k
1 vote

### DY-SV5W Voice Playback Module

You don't appear to have any pull-up resistors on the chip inputs that connect to the control switches. It's quite likely that they will be needed. There may be other problems but, you haven't posted ...
• 467k

### Dual Float Switches for a Boat's Bilge Pump

The system you show has a latching function and mostly does what you want. There is a problem, though: the pump startup current is taken up by the HIGH level switch, since there's a delay between that ...
Accepted

### Can I wire the PnP wire to ground?

No, you can't ground the black wire, it will damage the output. If you don't need the black wire, leave it unconnected.
• 164k

### Electronic bilge pump switch

I wouldn't do it with transistors. A relay will do this job rather nicely: simulate this circuit – Schematic created using CircuitLab With bilge empty, LOW and HIGH are open, A is at off (0V), ...

### Power circuit with a push button

I created a breakout board for this exact problem that uses a "smart on/off controller" IC, the ST6601. It's basically a little microcontroller that can get to a deep sleep current of .6uA. ...
1 vote

### Switch for switching between and/or gate

Table 1. Logic truth table. ...
• 178k

### Switch for switching between and/or gate

I agree with Transistor's truth table. Based on that, an all-mechanical solution takes one DPDT and two SPST switches per LED. The S1 input always goes to the source, and the S2 output always goes to ...
• 22k

### Can a switch be put on the collector side of npn BC547 rather than the base side?

Can I put the switch at the load side of the transistor rather than the base side? Will the circuit works the same as the first one? What difference will be there between these two configurations? ...
• 38.1k

### Can a switch be put on the collector side of npn BC547 rather than the base side?

Your two designs will have identical behaviour. The only reason you'd use a transistor at all is if you want to control the relay using a low power signal, such as the output from a microcontroller. ...
• 42.2k

### Can a switch be put on the collector side of npn BC547 rather than the base side?

In the first circuit the relay is turned on by the transistor when base current flows. In the second circuit the relay is turned on by the transistor only when the switch is also turned on. The switch ...
• 19k
1 vote

### Can a switch be put on the collector side of npn BC547 rather than the base side?

The two circuits are not the same. They achieve the same function in different ways. A significant difference between the two circuits is that in the right circuit, both the transistor and the switch ...
• 22k

### How to emulate a momentary push button with a SPST slide switch

You can replace push-button with Spst according schematic: Edit: For pin3 be delayed a little after pin1 use this schematic: So for pin1 use first schematic and for pin3 use second one. Both are ...
• 2,310