push-on-hold-off
github.com / kasbah
Simple power switch using a push button. Push to turn on, hold to turn off.
x
+
%
Digikey
Digikey
Mouser
Mouser
RS
RS
Newark
Newark
Farnell
Farnell

See a preview of the board and buy the parts from the kitnic.it page.

A power switch using a push button. It turns on with a single press and only turns off when you hold the button down. This could be used to get functionality similar to most laptops where a single press when on will initiate a "soft" shutdown but you can force a "hard" shutdown by holding it down.

The circuit is from this article.

The board is my own design and features:

  • Standard 0.1" spacing, fits neatly onto a breadboard
  • On-board button (and pins to connect your own)
  • Two LEDs indicate input and output power
  • Configurable to automatically turn on or stay off on initial power through a solder jumper (auto-off is the default)
  • Can switch 3-20V and up to 4A
 
ReferencesQtyDescriptionManufacturerMPNDigikeyMouserRSNewarkFarnell
C111uF 0603 X5RMurataGRM188R71E224KA88D490-3290-1-NDGRM188R71E224KA88D624249691R09491828900
C2110uF 0603 X5RTDKC1608X5R1A106M080AC445-6853-1-ND06036D106MAT2A788289304X32392211164
C410.1uF 0603 X5RKemetC0603C104K5RACTU399-5089-1-NDC0603C104K5RACTU801534772J59921288255
D11Diode MiniMELFLL4148LL4148FSCT-NDLL4148670882614M60037355513
LED1,LED220603 20mA yellowRohmSML-D12Y8WT86511-1582-1-ND5988150107F700802375R05851465989
Q1130V Vds, 3A Id, Dual HEXFET MOSFETInternational RectifierIRF7309PBFIRF7309PBFCT-NDIRF7309PBF542937719K82392468006
R1110k 0603VishayCRCW060310K0JNEA541-10KGCT-NDCRCW060310K0JNEAHP820692852K80661469749
R2,R42100k 0603VishayCRCW0603100KJNEA541-100KGCT-NDCRCW0603100KJNEAHP820691659M67631692517
R31300k 0603VishayCRCW0603300KFKEA311-300KGRCT-NDRC0603JR07300KL828061752K84091652871
R5, R621k 0603YageoRC0805FR-071KL311-1.00KCRCT-NDRC0805FR071KL618358382K75369237496
SW11Tactile switchFSM2JSMA450-1130-ND214375657479149192F28643801287