Beginner help connecting button to electric cabinet latch

Thread Starter

UnknownElementX

Joined Feb 20, 2019
11
I'm an absolute beginner looking to connect aN electronic cabinet latch (requiring a single .8 second 12v pulse to activate) to a push button switch. (the forum doesn't seem to allow me to post Amazon links so if you could tell me how to do that it would help)

Ideally I'd like to have it set up so that any press of the button (even if held down) only sends a single quick pulse of the .8 second 12v power (from battery or wall plus) to the switch to unlatch so that it doesn't burn out or overheat if the button stays depressed.

I have no familiarity with this stuff so any super simple solution in a compact setup with layman's terms descriptions would be wildly appreciated.

Thank you!
 

AlbertHall

Joined Jun 4, 2014
8,506
Normally you can copy the url and paste it into a message on here. If it won't allow that maybe it is because you are new here.
You could post the description line from amazon and we could search for that.

Do you know how much current the lock needs?

This sounds like a typical application for an NE555 or LMC555. It needs the chip, 3 capacitors, 3 resistors or thereabouts and possibly a relay.
Do you want to make this yourself or buy something to do the job?
 

Yaakov

Joined Jan 27, 2019
1,601
My first thought is too use a 555 IC, which is ubiquitous and about as simple as you can get. You can read about it here: https://www.allaboutcircuits.com/tools/555-timer-monostable-circuit/

The 555 can be used for all sorts of things, including what you want to do. Using a breadboard, you can prototype a circuit until it does just what you want, then move it to a more permanent arrangement on a soldered protoboard.

First get the circuit behaving properly, then read about the various things you need for a practical application (protection of the circuit, filtering, etc.) so it will keep working.

Plenty of folks here will help once you’ve gotten in up to your neck. They won’t let you drown but you’lll get a lot more response once you jump in the water because you’ll be asking how to swim rather than what it means to swim.

Start with that 555 link, see if it means anything useful to you, ask questions.

Grid luck!
 

Thread Starter

UnknownElementX

Joined Feb 20, 2019
11
Thank you for the quick responses. For this, finding something I could buy and plug together would be great, as I'm really just looking for a button/power source to get the latch working on this project. I'm willing to try and work it out if that isn't possible, I just don't know the lingo or how to read circuit diagrams to navigate even the 555 IC link.

The latch is "Atoplee DC 12V 0.43A/2A Mini Electric Bolt Lock for Cabinet Small Cabinet Lock/Solenoid Door Lock,2pcs (DC 12V,2A)" and I assume the button would be something like "10 Pack (NC ON-OFF) Black Cap Mini Momentary Push Buttons SPST Including 20 Solder-Free Quick Terminal Connectors | 7mm (17/64") Mount | 3A @ 12VDC Rated | 0.5A @ 120VAC | Normally Closed | PBS-111C"5CA3FE17-152F-4C56-BDF5-63F2A05B7280.jpegD0A57EAA-7F74-45DC-A3B0-F349F5C8A242.jpeg
 

Yaakov

Joined Jan 27, 2019
1,601
No, that module is the wrong type. The relay operates to delay the application of power.
It has NO and NC contacts on the relay.

Looking more carefully, I can't tell if it will operate as expected, but similar models offer enough flexibility to do the job. I don't think I would buy that one anyway, given the QC issues detailed in the comments.

I am sure some eBay seller must have an option with a better description. It will be very similar to this one.
 

Thread Starter

UnknownElementX

Joined Feb 20, 2019
11
Any suggestions for a better switch (I'm looking for a button with decent click and travel as this will sit below the base of a tilting object for a secret door project) and a power supply?

As to the module (other than the many DoA reviews) how would I set that up to send only one pulse for the required duration even if the button stays depressed? The description seems to suggest that module provides a delay and stays on. Or does that depend on how you wire/configure it?
 

AnalogKid

Joined Aug 1, 2013
8,138
A circuit that takes a signal that is either long or short and turns it into a fixed-length output pulse is called a monostable multivibrator. A 555 is good enough for this. The 555 cannot drive a 2 A load directly, so you will need an external power transistor. If you don't already have a power source, consider a 12 Vdc wall wart. Most computer stores have them, or they are online for under $5.

Where are you located?
What is your skill set for assembling a small circuit (10-ish components) on a piece of perf board? Soldering experience?

ak
 

Thread Starter

UnknownElementX

Joined Feb 20, 2019
11
I'm in southern California. I've soldered before but that's pretty much the extent of my electrical experience. I've never put a circuit together and don't have any familiarity with circuit components, unfortunately.
 

Thread Starter

UnknownElementX

Joined Feb 20, 2019
11
Looks like those are easy to come by even on amazon.

Will I also need a power transistor as you previously mentioned or can I attach a wall wart like the one below to this directly?

And any suggestions for an ideal switch?
235EDAFF-EFE8-4E88-B5C1-BA6FA0C8A028.jpeg 89D5EF0A-071F-4C2F-802D-29657F2EB88C.jpeg
 

Yaakov

Joined Jan 27, 2019
1,601
Any suggestions for a better switch (I'm looking for a button with decent click and travel as this will sit below the base of a tilting object for a secret door project) and a power supply?
This switch is of a much more reliable type: https://www.ebay.com/itm/ALCO-MSPM-101C-SPST-N-O-MOMENTARY-MINIATURE-PUSHBUTTON-SWITCH-SEALED-NOS/333071183583

A small switching supply like this one will work well: https://www.ebay.com/itm/12VDC-3A-5A-10A-20A-30A-50A-Regulated-Switching-Power-Supply-for-LED-Strip-Light/222908835014
 

Yaakov

Joined Jan 27, 2019
1,601
Looks like those are easy to come by even on amazon.

Will I also need a power transistor as you previously mentioned or can I attach a wall wart like the one below to this directly?

And any suggestions for an ideal switch?
View attachment 170566 View attachment 170567
The wall wart supply will work, but I would use the small switcher that I suggested or something like it, to make concealing it easier.
 

AlbertHall

Joined Jun 4, 2014
8,506
Looks like those are easy to come by even on amazon.

Will I also need a power transistor as you previously mentioned or can I attach a wall wart like the one below to this directly?

And any suggestions for an ideal switch?
The wall wart should probably be rated for more than 2A as it will also need to supply the relay on the timer and it would cause problems if it decided to limit the current.

For the switch, you need to take into account the thickness of whatever it will be mounted on.
 

Thread Starter

UnknownElementX

Joined Feb 20, 2019
11
Very much appreciated guys. I'm going to give the FRM01 a try. Any guidance on how to wire it and set it up for my use (or beginner tips to keep in mind)?
 

AlbertHall

Joined Jun 4, 2014
8,506
Have a look at the instructions I attached to post #12. This is clearly translated from the foreign and is a bit peculiar in places persevere.
You will need function 12.
There is a wiring diagram on page 6 - make very sure you get positive and negative the right way round.
And of course we will be here if you have any questions.
 

Thread Starter

UnknownElementX

Joined Feb 20, 2019
11
I also found some enhanced instructions here: https://www.thingiverse.com/thing:703067/files but I can't really decipher the wiring diagram. Is the power supply being split and fed to both sides of the FRM01, with the latch inserted between the power supply and the COM connection of the FRM01 on the neutral line, and the button wired to the CH1 connection and split off of the positive connection from the power supply?

Maybe you could list the wiring steps necessary here so I can compare to the diagram? (aka: First wire load/red/positive connection from power supply to NO connection on FRM01. Then wire neutral/black/negative connection from power supply to latch. Then wire latch to COM connection. Then wire Button to CH1 and wire button to split off of power supply to right side DC+ on FRM01.)

I'm assuming I'm reading this completely wrong, as I can't tell from this diagram where the various components sit on this diagram and where wires need to be split, connected, etc.
 

AlbertHall

Joined Jun 4, 2014
8,506
As you are using 12V for the lock and the board also needs 12V then the supply needs to be connected to both sides of the board.
Looking at the diagram in your version of the manual:
Both of the red balloons connect to power positive.
Both black balloons connect to power negative.
I don't know whether it matters which way round the power to the lock goes but as it has red and black wires I would assume the red is positive.
So, following the diagram, the lock black wire connects to the power negative black balloon and the lock red wire connects to the timer COM connector.
 
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