what's wrong with this circuit?

It is clunky and inelegant but biggest risk I can see is Q1 gate being overstressed, Vgsmax spec is 20V. push button contact welding possible if switch is puny.

Right. And the 2N2222 is only 40V rated. And U1 should not need a heatsink. And... oh, forget it.

Arie

He probably meant Q1. He obviously doesn't check his work.

It's impressive how much really bad circuit design gets done, and published.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

"john larkin" snipped-for-privacy@glen--canyon.com wrote in message news: snipped-for-privacy@4ax.com...

This might work, but may have issues if its own. Only one more transistor than the published circuit but no chips at all.

There's probably a better way to simulate a bouncy switch.

Version 4.1 SHEET 1 1252 2100 WIRE -288 -192 -864 -192 WIRE 32 -192 -288 -192 WIRE 576 -192 32 -192 WIRE 848 -192 576 -192 WIRE 960 -192 848 -192 WIRE 1152 -192 1056 -192 WIRE -288 -160 -288 -192 WIRE 32 -80 32 -192 WIRE 576 -80 576 -192 WIRE 848 -80 848 -192 WIRE -288 -48 -288 -80 WIRE -176 -48 -288 -48 WIRE -176 -16 -176 -48 WIRE -288 0 -288 -48 WIRE 848 32 848 0 WIRE 976 32 976 -144 WIRE 976 32 848 32 WIRE 848 80 848 32 WIRE -176 96 -176 64 WIRE -864 112 -864 -192 WIRE 32 128 32 0 WIRE 80 128 32 128 WIRE 208 128 160 128 WIRE 432 128 400 128 WIRE 576 128 576 0 WIRE 576 128 512 128 WIRE -448 144 -560 144 WIRE -416 144 -448 144 WIRE -288 144 -288 80 WIRE -288 144 -336 144 WIRE 32 192 32 128 WIRE 32 192 -80 192 WIRE 576 192 576 128 WIRE 688 192 576 192 WIRE 1152 192 1152 -192 WIRE -560 208 -560 144 WIRE -608 224 -704 224 WIRE 32 224 32 192 WIRE 96 224 32 224 WIRE 208 224 208 128 WIRE 208 224 160 224 WIRE 400 224 400 128 WIRE 448 224 400 224 WIRE 576 224 576 192 WIRE 576 224 512 224 WIRE 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288 720 WIRE 320 720 304 720 WIRE 400 720 400 528 WIRE 400 720 384 720 WIRE 688 720 688 560 WIRE 688 720 400 720 WIRE -160 816 -160 256 WIRE 304 816 304 720 WIRE 304 816 -160 816 WIRE -448 832 -448 144 WIRE -448 832 -560 832 WIRE -560 896 -560 832 WIRE -608 912 -624 912 WIRE -608 960 -704 960 WIRE -704 992 -704 960 WIRE -704 1312 -704 1072 WIRE -624 1312 -624 912 WIRE -624 1312 -704 1312 WIRE -560 1312 -560 976 WIRE -560 1312 -624 1312 WIRE -704 1360 -704 1312 WIRE -448 1392 -448 832 WIRE -496 1408 -512 1408 WIRE -496 1456 -592 1456 WIRE -592 1488 -592 1456 WIRE -592 1808 -592 1568 WIRE -512 1808 -512 1408 WIRE -512 1808 -592 1808 WIRE -448 1808 -448 1472 WIRE -448 1808 -512 1808 WIRE -592 1856 -592 1808 FLAG -864 672 0 FLAG -176 96 0 FLAG -704 1360 0 FLAG -592 1856 0 SYMBOL npn 96 304 M0 SYMATTR InstName Q1 SYMATTR Value BSS64A SYMBOL res 16 -96 R0 SYMATTR InstName R1 SYMATTR Value 33k SYMBOL res 128 400 R0 WINDOW 0 -43 38 Left 2 WINDOW 3 -64 67 Left 2 SYMATTR InstName R2 SYMATTR Value 100k SYMBOL npn 512 304 R0 SYMATTR InstName Q2 SYMATTR Value BSS64A SYMBOL res 592 -96 M0 SYMATTR InstName R3 SYMATTR Value 33k SYMBOL res 496 400 M0 WINDOW 0 -36 45 Left 2 WINDOW 3 -57 70 Left 2 SYMATTR InstName R4 SYMATTR Value 100k SYMBOL res 176 112 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R5 SYMATTR Value 47k SYMBOL res 528 112 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R6 SYMATTR Value 47k SYMBOL cap 288 704 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C3 SYMATTR Value 1n SYMBOL cap 384 736 M270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName C4 SYMATTR Value 1n SYMBOL sw -560 304 M180 SYMATTR InstName S1 SYMATTR Value SWCH SYMBOL voltage -704 288 R0 WINDOW 3 -366 421 Left 2 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR Value PULSE(0 2 {1/4/F} 10u 10u {1/4/F} {1/F} 5) SYMATTR InstName V1 SYMBOL voltage -864 96 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V2 SYMATTR Value 49 SYMBOL res -320 128 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R8 SYMATTR Value 22 SYMBOL cap -304 368 R0 SYMATTR InstName C5 SYMATTR Value 1n SYMBOL res -304 -16 R0 SYMATTR InstName R9 SYMATTR Value 10Meg SYMBOL res -304 -176 R0 SYMATTR InstName R10 SYMATTR Value 220k SYMBOL res -192 -32 R0 SYMATTR InstName R11 SYMATTR Value 22k SYMBOL cap 160 208 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C1 SYMATTR Value 47p SYMBOL cap 512 208 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C2 SYMATTR Value 47p SYMBOL diode 192 464 R0 SYMATTR InstName D2 SYMATTR Value 1N914 SYMBOL diode 384 464 R0 WINDOW 0 -23 -3 Left 2 WINDOW 3 -70 63 Left 2 SYMATTR InstName D3 SYMATTR Value 1N914 SYMBOL res -96 464 R0 SYMATTR InstName R7 SYMATTR Value 220k SYMBOL res 672 464 R0 SYMATTR InstName R12 SYMATTR Value 220k SYMBOL npn 784 400 R0 SYMATTR InstName Q3 SYMATTR Value BSS64A SYMBOL res 832 -96 R0 SYMATTR InstName R13 SYMATTR Value 10k SYMBOL res 832 64 R0 SYMATTR InstName R14 SYMATTR Value 22k SYMBOL pmos 1056 -144 M270 WINDOW 0 -19 56 VLeft 2 WINDOW 3 77 118 VLeft 2 SYMATTR InstName M1 SYMATTR Value ZXMP10A18G SYMBOL res 1136 176 R0 SYMATTR InstName R15 SYMATTR Value 2k SYMBOL sw -560 880 R0 SYMATTR InstName S2 SYMATTR Value SWCH SYMBOL voltage -704 976 M0 WINDOW 3 43 129 Left 2 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR Value PULSE(0 2 {.23/F} 1u 1u {1/2/F/200} {1/F/200} 5) SYMATTR InstName V3 SYMBOL sw -448 1376 R0 SYMATTR InstName S3 SYMATTR Value SWCH SYMBOL voltage -592 1472 M0 WINDOW 3 59 141 Left 2 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR Value PULSE(0 2 {.75/F} 1u 1u {1/2/F/200} {1/F/200} 5) SYMATTR InstName V4 TEXT -1072 584 Left 2 !.tran 10 startup TEXT -1072 752 Left 2 !.param F=0.5 TEXT -1080 800 Left 2 !.MODEL SWCH SW(Ron=.1 Roff=10Meg Vt=1)

You might say 40V V_CEO but the base is not open. 60V V_CBO suggests that it will work here.

Switch welding yes that could be a problem. but there's no easy cure. however with 6 inverters there's probably a better way to make a flip-flop

Q1 V_GS - yes, 56K in series with Q3 collector will fix that

C2 is way too small to reliably reset U1 given the soft start provided by C3 increasing C2 to 10uF is one possible fix.

These are CMOS parts, "VCC" should be "VDD"

What I'd do

Change q2 to pnp and flip that neighbourhood around to instead regulate a 33V VSS and have VDD as 48V

Instead of C2 use a resistor, and for R2 use a 3.9V zener (or some LEDs). the soft start now produces a reset signal until the voltage (VDD-VSS) exceeds 5v

Now 15V is available to drive the gate.

One possilble inverter flip-flop

VDD T | --- 100nF LED +-o o---+---||---VSS | | | LED | 100k | | | +--|>o--->|--+--|>o--+---|>o-+----> to Q1 gate | | | 10K +-----[10k]-----+ | VSS

Now the switch only passes logic currents, so no welding. On the down side the switch is no longer ground referenced.

On 17/10/2025 05:42, Edward Rawde wrote:

Thanks, that provoked a few ideas. I simplified the MOSFET gate drive, protected the eccles-jordan transistor bases from reverse bias and increased the commutating capacitors so they can do the contact debouncing. To tolerate low quality pushbutton contacts the open circuit voltage is above 12V to break oxide films, the peak make current above

Version 4 SHEET 1 1348 2100 WIRE -288 -128 -864 -128 WIRE 32 -128 -288 -128 WIRE 576 -128 32 -128 WIRE 736 -128 576 -128 WIRE 928 -128 832 -128 WIRE 576 -80 576 -128 WIRE -288 0 -288 -128 WIRE 32 48 32 -128 WIRE 576 48 576 0 WIRE 752 48 752 -80 WIRE 752 48 576 48 WIRE 576 96 576 48 WIRE -864 112 -864 -128 WIRE -448 144 -560 144 WIRE -400 144 -448 144 WIRE -288 144 -288 80 WIRE -288 144 -400 144 WIRE 928 192 928 -128 WIRE -560 208 -560 144 WIRE -608 224 -704 224 WIRE 32 224 32 128 WIRE 80 224 32 224 WIRE 208 224 160 224 WIRE 432 224 400 224 WIRE 576 224 576 176 WIRE 576 224 512 224 WIRE -608 272 -624 272 WIRE -288 272 -288 144 WIRE -208 272 -288 272 WIRE 32 272 32 224 WIRE 32 272 -80 272 WIRE 576 272 576 224 WIRE 688 272 576 272 WIRE -704 304 -704 224 WIRE 32 304 32 272 WIRE 576 304 576 272 WIRE 144 352 96 352 WIRE 208 352 400 224 WIRE 208 352 144 352 WIRE 400 352 208 224 WIRE 480 352 400 352 WIRE 512 352 480 352 WIRE -208 368 -208 272 WIRE 208 384 208 352 WIRE 400 384 400 352 WIRE -80 480 -80 272 WIRE 688 480 688 272 WIRE 144 528 144 352 WIRE 480 528 480 352 WIRE -864 624 -864 192 WIRE -704 624 -704 384 WIRE -704 624 -864 624 WIRE -624 624 -624 272 WIRE -624 624 -704 624 WIRE -560 624 -560 288 WIRE -560 624 -624 624 WIRE -208 624 -208 448 WIRE -208 624 -560 624 WIRE 32 624 32 400 WIRE 32 624 -208 624 WIRE 144 624 144 592 WIRE 144 624 32 624 WIRE 480 624 480 592 WIRE 480 624 144 624 WIRE 576 624 576 400 WIRE 576 624 480 624 WIRE 928 624 928 272 WIRE 928 624 576 624 WIRE -864 672 -864 624 WIRE -80 720 -80 560 WIRE 208 720 208 448 WIRE 208 720 -80 720 WIRE 224 720 208 720 WIRE 304 720 288 720 WIRE 320 720 304 720 WIRE 400 720 400 448 WIRE 400 720 384 720 WIRE 688 720 688 560 WIRE 688 720 400 720 WIRE -288 816 -288 272 WIRE -160 816 -288 816 WIRE 304 816 304 720 WIRE 304 816 -80 816 WIRE -448 832 -448 144 WIRE -448 832 -560 832 WIRE -560 896 -560 832 WIRE -608 912 -624 912 WIRE -608 960 -704 960 WIRE -704 992 -704 960 WIRE -704 1104 -704 1072 WIRE -624 1104 -624 912 WIRE -624 1104 -704 1104 WIRE -560 1104 -560 976 WIRE -560 1104 -624 1104 WIRE -704 1152 -704 1104 WIRE -448 1184 -448 832 WIRE -496 1200 -512 1200 WIRE -496 1248 -592 1248 WIRE -592 1280 -592 1248 WIRE -592 1424 -592 1360 WIRE -512 1424 -512 1200 WIRE -512 1424 -592 1424 WIRE -448 1424 -448 1264 WIRE -448 1424 -512 1424 WIRE -592 1472 -592 1424 FLAG -864 672 0 FLAG -704 1152 0 FLAG -592 1472 0 FLAG -400 144 PUSHBUTTON SYMBOL npn 96 304 M0 SYMATTR InstName Q1 SYMATTR Value BSS64A SYMBOL res 16 32 R0 SYMATTR InstName R5 SYMATTR Value 100k SYMBOL npn 512 304 R0 SYMATTR InstName Q2 SYMATTR Value BSS64A SYMBOL res 592 80 M0 SYMATTR InstName R9 SYMATTR Value 15k SYMBOL res 176 208 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R6 SYMATTR Value 470k SYMBOL res 528 208 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R7 SYMATTR Value 470k SYMBOL cap 288 704 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C1 SYMATTR Value 1µ SYMBOL cap 384 736 M270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName C2 SYMATTR Value 1µ SYMBOL sw -560 304 M180 SYMATTR InstName S1 SYMATTR Value SWCH SYMBOL voltage -704 288 R0 WINDOW 3 -366 421 Left 2 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR Value PULSE(0 2 {1/4/F} 10u 10u {1/4/F} {1/F} 5) SYMATTR InstName V1 SYMBOL voltage -864 96 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V2 SYMATTR Value 49 SYMBOL res -304 -16 R0 SYMATTR InstName R1 SYMATTR Value 470k SYMBOL res -224 352 R0 SYMATTR InstName R2 SYMATTR Value 470k SYMBOL diode 384 384 R0 WINDOW 0 -23 -3 Left 2 WINDOW 3 -70 63 Left 2 SYMATTR InstName D3 SYMATTR Value 1N4148 SYMBOL res -96 464 R0 SYMATTR InstName R4 SYMATTR Value 470k SYMBOL res 672 464 R0 SYMATTR InstName R10 SYMATTR Value 470k SYMBOL pmos 832 -80 M270 WINDOW 0 -19 56 VLeft 2 WINDOW 3 77 118 VLeft 2 SYMATTR InstName M1 SYMATTR Value ZXMP10A18G SYMBOL res 912 176 R0 SYMATTR InstName RLOAD SYMATTR Value 2k SYMBOL sw -560 880 R0 SYMATTR InstName S2 SYMATTR Value SWCH SYMBOL voltage -704 976 M0 WINDOW 3 43 129 Left 2 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR Value PULSE(0 2 {.245/F} 1u 1u 1m 2m 5) SYMATTR InstName V3 SYMBOL sw -448 1168 R0 SYMATTR InstName S3 SYMATTR Value SWCH SYMBOL voltage -592 1264 M0 WINDOW 3 59 141 Left 2 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR Value PULSE(0 2 {.501/F} 1u 1u 1m 2m 5) SYMATTR InstName V4 SYMBOL diode 192 384 R0 WINDOW 0 -23 -3 Left 2 WINDOW 3 -70 63 Left 2 SYMATTR InstName D2 SYMATTR Value 1N4148 SYMBOL diode 496 592 R180 WINDOW 0 24 64 Left 2 WINDOW 3 24 0 Left 2 SYMATTR InstName D4 SYMATTR Value 1N4148 SYMBOL diode 160 592 R180 WINDOW 0 24 64 Left 2 WINDOW 3 24 0 Left 2 SYMATTR InstName D1 SYMATTR Value 1N4148 SYMBOL res 560 -96 R0 SYMATTR InstName R8 SYMATTR Value 3.3k SYMBOL res -64 800 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R3 SYMATTR Value 220 TEXT -1072 584 Left 2 !.tran 10 startup TEXT -1072 752 Left 2 !.param F=0.5 TEXT -1080 800 Left 2 !.MODEL SWCH SW(Ron=.1 Roff=100Meg Vt=1) TEXT 816 944 Left 2 ;EPW SED OCT 2025 TEXT 672 1008 Left 2 ;INSPIRED BY EDWARD RAWDE TEXT 632 1072 Left 2 ;TOGGLE POWER ON PUSH BUTTON TEXT -384 952 Left 2 ;BOUNCE ON MAKE TEXT -392 1320 Left 2 ;BOUNCE ON BREAK

piglet

"piglet" snipped-for-privacy@hotmail.com wrote in message news:10cubn8$1cq2k$ snipped-for-privacy@dont-email.me...

...

Yes. Excellent refinement.

Now about the same component count as the EDN circuit minus the two logic chips.

BSS64 seems to be obsolete so I changed to BC846B.

I also changed the MOSFET and simulated 2A load.

No heatsinks required at all but R9 should be > 0.1W.

I guess that's $100 USD each.

Version 4.1 SHEET 1 1348 2100 WIRE -128 -144 -704 -144 WIRE 32 -144 -128 -144 WIRE 576 -144 32 -144 WIRE 656 -144 576 -144 WIRE 736 -144 656 -144 WIRE 912 -144 832 -144 WIRE 992 -144 912 -144 WIRE -128 -96 -128 -144 WIRE 32 -96 32 -144 WIRE 576 -96 576 -144 WIRE 576 32 576 -16 WIRE 672 32 576 32 WIRE 752 32 752 -96 WIRE 752 32 672 32 WIRE -128 48 -128 -16 WIRE -96 48 -128 48 WIRE 208 48 -16 48 WIRE 400 48 208 48 WIRE 208 80 208 48 WIRE 400 80 400 48 WIRE 576 80 576 32 WIRE 32 176 32 -16 WIRE 80 176 32 176 WIRE 400 176 400 144 WIRE 400 176 160 176 WIRE 992 176 992 -144 WIRE 208 240 208 144 WIRE 448 240 208 240 WIRE 576 240 576 160 WIRE 576 240 528 240 WIRE -704 256 -704 -144 WIRE 208 272 208 240 WIRE 400 272 400 176 WIRE -304 288 -400 288 WIRE -224 288 -304 288 WIRE -128 288 -128 48 WIRE -128 288 -224 288 WIRE -400 352 -400 288 WIRE -448 368 -544 368 WIRE 32 368 32 176 WIRE 80 368 32 368 WIRE 208 368 208 336 WIRE 208 368 160 368 WIRE 400 368 400 336 WIRE 448 368 400 368 WIRE 576 368 576 240 WIRE 576 368 528 368 WIRE -448 416 -464 416 WIRE -544 448 -544 368 WIRE 32 448 32 368 WIRE 576 448 576 368 WIRE -128 496 -128 288 WIRE 208 496 400 368 WIRE 208 496 96 496 WIRE 400 496 208 368 WIRE 512 496 400 496 WIRE 208 528 208 496 WIRE 400 528 400 496 WIRE -704 624 -704 336 WIRE -544 624 -544 528 WIRE -544 624 -704 624 WIRE -464 624 -464 416 WIRE -464 624 -544 624 WIRE -400 624 -400 432 WIRE -400 624 -464 624 WIRE -128 624 -128 576 WIRE -128 624 -400 624 WIRE 32 624 32 544 WIRE 32 624 -128 624 WIRE 208 624 208 592 WIRE 208 624 32 624 WIRE 400 624 400 592 WIRE 400 624 208 624 WIRE 576 624 576 544 WIRE 576 624 400 624 WIRE 992 624 992 256 WIRE 992 624 576 624 WIRE -704 672 -704 624 WIRE -304 832 -304 288 WIRE -304 832 -416 832 WIRE -416 896 -416 832 WIRE -464 912 -480 912 WIRE -464 960 -560 960 WIRE -560 992 -560 960 WIRE -560 1104 -560 1072 WIRE -480 1104 -480 912 WIRE -480 1104 -560 1104 WIRE -416 1104 -416 976 WIRE -416 1104 -480 1104 WIRE -560 1152 -560 1104 WIRE -304 1184 -304 832 WIRE -352 1200 -368 1200 WIRE -352 1248 -448 1248 WIRE -448 1280 -448 1248 WIRE -448 1424 -448 1360 WIRE -368 1424 -368 1200 WIRE -368 1424 -448 1424 WIRE -304 1424 -304 1264 WIRE -304 1424 -368 1424 WIRE -448 1472 -448 1424 FLAG -704 672 0 FLAG -560 1152 0 FLAG -448 1472 0 FLAG -224 288 PUSHBUTTON FLAG 672 32 gate FLAG 656 -144 v48 FLAG 912 -144 sw SYMBOL npn 96 448 M0 SYMATTR InstName Q1 SYMATTR Value BC846B SYMBOL res 16 -112 R0 SYMATTR InstName R5 SYMATTR Value 100k SYMBOL npn 512 448 R0 SYMATTR InstName Q2 SYMATTR Value BC846B SYMBOL res 592 64 M0 WINDOW 0 -41 38 Left 2 WINDOW 3 -49 72 Left 2 SYMATTR InstName R9 SYMATTR Value 15k SYMBOL res 176 352 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R6 SYMATTR Value 470k SYMBOL res 544 352 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R7 SYMATTR Value 470k SYMBOL sw -400 448 M180 SYMATTR InstName S1 SYMATTR Value SWCH SYMBOL voltage -544 432 R0 WINDOW 3 -366 421 Left 2 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR Value PULSE(0 2 {1/4/F} 10u 10u {1/4/F} {1/F} 5) SYMATTR InstName V1 SYMBOL voltage -704 240 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V2 SYMATTR Value 49 SYMBOL res -112 -112 M0 SYMATTR InstName R1 SYMATTR Value 470k SYMBOL res -112 480 M0 SYMATTR InstName R2 SYMATTR Value 470k SYMBOL res 544 224 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R10 SYMATTR Value 470k SYMBOL pmos 832 -96 M270 WINDOW 0 -19 56 VLeft 2 WINDOW 3 76 99 VLeft 2 SYMATTR InstName M1 SYMATTR Value Si7489DP SYMBOL res 976 160 R0 SYMATTR InstName RLOAD SYMATTR Value 24 SYMBOL sw -416 880 R0 SYMATTR InstName S2 SYMATTR Value SWCH SYMBOL voltage -560 976 M0 WINDOW 3 43 129 Left 2 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR Value PULSE(0 2 {.245/F} 1u 1u 1m 2m 5) SYMATTR InstName V3 SYMBOL sw -304 1168 R0 SYMATTR InstName S3 SYMATTR Value SWCH SYMBOL voltage -448 1264 M0 WINDOW 3 59 141 Left 2 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR Value PULSE(0 2 {.501/F} 1u 1u 1m 2m 5) SYMATTR InstName V4 SYMBOL diode 416 592 R180 WINDOW 0 40 32 Left 2 WINDOW 3 -95 33 Left 2 SYMATTR InstName D4 SYMATTR Value 1N4148 SYMBOL diode 224 592 R180 WINDOW 0 -38 32 Left 2 WINDOW 3 41 30 Left 2 SYMATTR InstName D1 SYMATTR Value 1N4148 SYMBOL res 560 -112 R0 SYMATTR InstName R8 SYMATTR Value 3.3k SYMBOL res 0 32 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R3 SYMATTR Value 220 SYMBOL diode 224 336 R180 WINDOW 0 -40 36 Left 2 WINDOW 3 39 35 Left 2 SYMATTR InstName D2 SYMATTR Value 1N4148 SYMBOL cap 192 80 R0 SYMATTR InstName C3 SYMATTR Value 1µ SYMBOL cap 384 144 M180 WINDOW 0 24 56 Left 2 WINDOW 3 24 8 Left 2 SYMATTR InstName C4 SYMATTR Value 1µ SYMBOL diode 416 336 R180 WINDOW 0 40 35 Left 2 WINDOW 3 -98 33 Left 2 SYMATTR InstName D3 SYMATTR Value 1N4148 SYMBOL res 64 160 M90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R4 SYMATTR Value 470k TEXT -912 584 Left 2 !.tran 10 startup TEXT -928 752 Left 2 !.param F=0.5 TEXT -936 800 Left 2 !.MODEL SWCH SW(Ron=.1 Roff=100Meg Vt=1) TEXT 696 816 Left 2 ;EPW SED OCT 2025 TEXT 576 880 Left 2 ;INSPIRED BY EDWARD RAWDE TEXT 544 944 Left 2 ;TOGGLE POWER ON PUSH BUTTON TEXT -240 952 Left 2 ;BOUNCE ON MAKE TEXT -248 1320 Left 2 ;BOUNCE ON BREAK