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How do I flash LED with signal from 555 timer ONLY when button is pressed?

Connect the switch between the output of the Schmidt trigger and the cathode of the LED.
WhatRoughBeast's user avatar
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How do I flash LED with signal from 555 timer ONLY when button is pressed?

Put the switch from the LED cathode to ground or in the VCC line of the 555.
RoyC's user avatar
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Driving a power MOSFET successfully

I believe you've got it right. 24V is fairly close to the maximum mosfet gate voltage of 30. I might go down to 20. Notice that you will be connecting the low side of your bridge rectifier to gnd. You ...
Drew's user avatar
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4 votes
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Voltage drop issues in LTspice simulation for buck converter using SW model

The "on" resistance of your switches is 1 ohm. You don't have a control loop around your buck to regulate the output voltage, so your output will drop in proportion to the effective source ...
John D's user avatar
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NC switch circuit with transistor

If you insist on using BJTs, a lot depends on the current that can be drawn by your "circuit". If it's less than 100mA or so, a single BJT can work: simulate this circuit – Schematic ...
Simon Fitch's user avatar
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Float Switch and relay for pump

Theoretically, the combination of this float switch and the relay should work and it won't consume any current as long as the switch is off. However, I would not trust the safety of these float ...
Fredled's user avatar
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Help reading DP4T slide switch schematic

I read this as: Contacts for pins 3 and 8 are wider than the others. So when the switch is all the way to the right, Position 1, Pole A pin 1 goes to pin 3 and Pole B pin 6 goes to pin 8. Sliding one ...
Kurt Sanger's user avatar
2 votes

High-side load switch that is on by default

You can have a single package solution by using a double 2N7002 in a 6-pin package, e.g. 2N7002DW, 2N7000VC, etc. So we end up with just 3 resistors and a single double-mosfet package: simulate this ...
Kuba hasn't forgotten Monica's user avatar
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Switching power and controlling RPi GPIO pins with a single rocker switch

There are a couple options, the first one perhaps you haven't considered. It should be possible to configure the RPi with a read-only file system (if your application doesn't need to write to disk), ...
Chris Knudsen's user avatar
1 vote

Charge batteries in parallel, discharge in series

Yes, it's possible, but fraught with a few problems: Balancing is trickier While in series, one of the two batteries will be the first to be emptied; when its BMS shuts it down, the load will be ...
Davide Andrea's user avatar
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Do 240V AC switches only need to open the active wire?

In this case it's ok to just switch the hot (brown) leg. Even better, your plug is polarized with a ground, so you can be assured you're switching hot.
hacktastical's user avatar
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Do 240V AC switches only need to open the active wire?

Given the specifics you have posted, an integral LED light fitting in a country with polarised sockets, then from a safety perspective I see absolutely no problem with switching just the live ...
Peter Green's user avatar
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2 votes
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I could not manage to use Switch Component in LTspice

I just don't have your problems: But since you provide no additional circuit details and have chosen to show only a little part, it's difficult to say much more. The above is the complete circuit. ...
periblepsis's user avatar
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1 vote
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Need help identifying a rotary switch component

From a google image search for "rotary quadrature encoder" found an in-stock Panasonic EVQ-VVD00203B on a distributor website: The datasheet has the following picture which looks to match ...
Chester Gillon's user avatar
2 votes

Vending machine motor: simple DC motor with microswitch, one revolution

I work on these units, testing and repairing them for in-service vending machines. Have restored hundreds of them. Couple of things, the most common issue is that the microswitches become excessively ...
Steve McDonald's user avatar
1 vote
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Circuit for rebooting by pressing momentary switches

The buttons pull the lines low, and this is using inverse logic. If either of the button inputs is high, then that indicates not pressed, and thus not resetting. Thus it should only pull reset low if ...
user1937198's user avatar
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Seemingly dielectric grease in my rotary switch

It’s silicone grease. The reason they put it in the switch is for lubrication. Moving parts tend to need lubrication to reduce wear and make them easier to move. That the grease is not conductive has ...
GodJihyo's user avatar
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1 vote
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Seemingly dielectric grease in my rotary switch

It's insulating, but enough of the large (for 2.5A) contact surfaces will make contact through the grease to conduct properly. The grease serves to keep debris off of the contact surfaces and prevent ...
vir's user avatar
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How does one connect a DPDT Push switch?

As you state you want the first press to switch (and maintain) the ON state, then a second press should turn the circuit OFF. This is often known as a "Latching" switch, or in this case an &...
Nedd's user avatar
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How does one connect a DPDT Push switch?

MHPS2273 is a latching DPDT key switch. It appears that you require the two contacts to be connected in parallel. The switch is to be wired as shown.
vu2nan's user avatar
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How does one connect a DPDT Push switch?

Switches have two types of connections, poles and throws. A DPDT switch has two poles and for each pole there are two throws. The poles are the common connection, the throws are the switched ...
GodJihyo's user avatar
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2 votes

How to use one USB-C port between 2x ESP32-S3 - Switched by toggle switch?

Have you considered using a cheap USB hub IC (like this one)? The USB bus is hub based and will mean that both downstream MCUs will be available to the host simultaneously on different addresses. No ...
AidenDawn's user avatar
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ESP12 to switch computer power

Ex 1 will not work, it won't do anything. Ex 2 should work. The only problem is, you need to know which pin on the motherboard is ground and which is the button input that should be connected to ...
Justme's user avatar
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Low power toggle switch

There's no real reason to use a 555-like as a toggle latch, when you can just use simple low-power logic to accomplish the same thing. For the most basic option, you can hook up a D-type flip flop ...
Hearth's user avatar
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1 vote

Low power toggle switch

You might try using a CMOS version of the 555, according to the datasheet for the LMC555 the supply current is maximum 400 uA @ 12 V. The TLC555 has a higher maximum voltage rating (18 V vs. 15 V) and ...
GodJihyo's user avatar
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2 votes

Searching for a high side switch with integrated current sensing

On a quick search on the TI High-side switches which is filtered on: Operating voltage >= 24 V Current >= 6 A There is: TPS281C30 : 60-V tolerant, 30-mΩ 6-A single-channel high-side switch ...
Chester Gillon's user avatar
2 votes
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Transistor as a switch with square wave input

This circuit may serve your purposes simulate this circuit – Schematic created using CircuitLab If the CNTRL input is below 4.3 V, the LED will be on. If the CNTRL input is above 4.3 V, the LED ...
Math Keeps Me Busy's user avatar
2 votes

EFT generator circuit

Some approx. numbers. SiC MOSFET, reverse transfer capacitance 100 pF. Drain voltage 1000 V. Miller charge is thus 100 nC. We need to fill this in 6 ns, so we need about 16 A of gate current. If we ...
tobalt's user avatar
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What's the name of the device that reverses on-off state based on second power input on-off?

relay noun /ˈriːleɪ/ an electrical device, typically incorporating an electromagnet, which is activated by a current or signal in one circuit to open or close another circuit. simulate this circuit &...
Transistor's user avatar
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What kind of switch is this surface mount component with no actuator?

Looks like a vibration switch similar to these:
Spehro Pefhany's user avatar
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MOSFET keeps detonating

With an exposed screw switch driving the gate, make R1 47kΩ, and add gate-source overvoltage protection.
Kuba hasn't forgotten Monica's user avatar
1 vote
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How do I successfully drive this MOSFET for a dump load resistor with a wind turbine?

How do I successfully drive this MOSFET for a dump load resistor with a wind turbine? My 1st suggestion allows the MOSFET to be driven from a ground referenced system: - Derive a 15 volt supply from ...
Andy aka's user avatar
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1 vote

MOSFET keeps detonating

RE-EDITED ANSWER The MOSFET failed to open because the R1 is 1M Ohms and it's way too much. When SW1 closes, Q1 is conducting because gate voltage is lower than source voltage (battery voltage in your ...
Fredled's user avatar
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3 votes

MOSFET keeps detonating

It sounds like the rocket arming screw switch is likely exposed to the atmosphere so, when the rocket is accelerating through the atmosphere, it probably picks up enough friction charge from the air ...
Andy aka's user avatar
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0 votes

MOSFET keeps detonating

If this is an external switch, you may want to put a ESD protection diode to make sure external voltage don't max out Vgs
Voltage Spike's user avatar
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1 vote

MOSFET keeps detonating

Insufficient gate voltage. You need 10V. Vgth is the value where conduction barely starts which is not your goal. You're interested in when the rated RDSon is achieved. You need a logic level MOSFET. ...
DKNguyen's user avatar
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Modify headphone jack to not mute speakers when plugged in (Yamaha HS4)

It might be easier to get a "line (RCA) to headphone (3.5mm)" amplifier and plug it into the "LINE 2" jacks. Then, you use the volume control on the source to adjust both the ...
MOSFET's user avatar
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1 vote

Modify headphone jack to not mute speakers when plugged in (Yamaha HS4)

What you seek may not be possible, or if it is, you need schematics instead of the signal flow diagram. What the headphone connector does is that when there is no phones inserted, the connector shorts ...
Justme's user avatar
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1 vote

Modify headphone jack to not mute speakers when plugged in (Yamaha HS4)

The pad labeled "HP DET" is what is telling the power amp to turn on or off. Desolder the wire, find another pad that it connects to with the headphones removed (RCH or LCH, by the look of ...
vir's user avatar
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