On Sat, 3 Oct 2015 20:42:59 -0400, "Tom Miller" <tmiller11147@verizon.net> wrote:> >"rickman" <gnuarm@gmail.com> wrote in message >news:mupjij$k5a$1@dont-email.me... >> On 10/3/2015 5:57 PM, Tom Miller wrote: >>> >>> "rickman" <gnuarm@gmail.com> wrote in message >>> news:muph5o$88r$2@dont-email.me... >>>> On 10/3/2015 4:58 PM, John Larkin wrote: >>>>> On Sat, 3 Oct 2015 11:09:40 -0700 (PDT), dagmargoodboat@yahoo.com >>>>> wrote: >>>>> >>>>> >>>>> PV optocouplers are cool for driving isolated gates, but maybe not >>>>> available in your junk box. >>>>> >>>>> I'm designing a kilovolt-range linear voltage regulator, and a PV is a >>>>> really easy way to drive the pass transistor gate. >>>>> >>>>> Hey, a packaged SIP dc/dc converter would make a nice SSR gate driver. >>>>> $4 or something from Mouser. >>>> >>>> That is the point of this circuit. A PV photocoupler needs a power >>>> source. This circuit *is* the power source. >>>> >>>> >>> >>> No, a PV optocoupler makes it own voltage. Just add it to the 12 volts >>> to drive the gate. >> >> Since when? They use a phototransistor, not a PV solar cell. >> >> -- >> >> Rick > >I guess that's why they call them PV optocouplers.A phototransistor optocoupler will generate a little voltage on the output side, not enough to be useful for anything I can imagine.
A very silly circuit
Started by ●October 3, 2015
Reply by ●October 3, 20152015-10-03
Reply by ●October 3, 20152015-10-03
On 10/3/2015 8:48 PM, dagmargoodboat@yahoo.com wrote:> On Saturday, October 3, 2015 at 8:37:48 PM UTC-4, rickman wrote: >> On 10/3/2015 8:26 PM, dagmargoodboat@yahoo.com wrote: >>> On Saturday, October 3, 2015 at 7:45:02 PM UTC-4, Jim Thompson wrote: >>>> On Sat, 3 Oct 2015 11:09:40 -0700 (PDT), dagmargoodboat@yahoo.com >>>> wrote: >>>> >>>>> 12v automotive SSR, to replace a failed $35 unit in my car. >>>>> >>>>> Q3 >>>>> | |-------+---O >>>>> | |<-. | >>>>> D2 .---+-------+---' |--+ .---' >>>>> .-----. | |C1 | | / \ TVS >>>>> .--------------------|~ +|--' |10nF .-. R4 | --- >>>>> | T1b 500uH | | --- | | 22K | | >>>>> '-----. . . . .------|~ -|--. --- '-' | | >>>>> '-'-'-'-' '-----' | | | | | >>>>> --------- '---+-------+--------+----+---O >>>>> --------- >>>>> .-.-.-.-. >>>>> .------' ' | ' '-------. >>>>> | T1a| 1mH | >>>>> | | | >>>>> O--------+----+----. | >>>>> | | | | >>>>> | .-. .-. | >>>>> | R1 | | R2 | | | >>>>> |10K | | 10K | | | >>>>> | '-' '-' | >>>>> | | ===== | | >>>>> \| | .-.-. | |/ >>>>> |---+--' ' '--+----| >>>>> .<| T1c |>. >>>>> | Q1 10uH Q2 | >>>>> | | >>>>> '----------+-----------' >>>>> | >>>>> .-. >>>>> | | R3 >>>>> | | 470 >>>>> '-' >>>>> | >>>>> | >>>>> LED1 V ~~> >>>>> --- >>>>> | >>>>> | >>>>> V D1 >>>>> --- >>>>> | >>>>> O------------' >>>>> >>>> >>>> [snip] >>>> >>>> How much current in the load? >>> >>> I don't actually know. The hypothetical load was an Acura radiator cooling >>> fan motor, whatever that draws. >>> >>>> Might have some SOA problems with the >>>> soft turn-on/turn-off?? >>> >>> I don't think so, but I didn't check. The switching times are well under 1mS, >>> purposely, with the gate capacitor there to intentionally slow things >>> down. Lowering C1's value speeds the switching, if needed. >>> >>> Okay, I just checked the SOA on a 1.2 milliohm FET, and it looks like 100uS >>> switching is just enough to avoid SOA up to 10A (for this random monster FET). >>> It might need a tougher FET or slightly faster switching to be solid. Unknown, >>> since the load is a mystery. >>> >>> Right now it switches Q3 'on' in 30uS (fan-start, the worst case load) and 'off' >>> in 120uS. Not bad, but might need beefing. >>> >>>> Might make a Schmitt arrangement, charge up cap _then_ connect to gate >>>> and vice versa for turn-off. >>> >>> Yup. Hate to use extra parts though, if avoidable. In your world parts are >>> free. In mine they have to be bought, inventoried, and soldered. >> >> If you are actually going to build this, > > I'm not building it, that's why it's a very silly circuit. I already swapped > in a spare relay from an unused accessory. This was just for fun, to see > what it might take. > >> why not use any of the many SSR >> devices in a package? What will this circuit do that a commercial unit >> won't? This looks like a much larger circuit than you could do with an >> SSR. > > Will it fit in a ~2 x 1 x .5" package, to fit in the original space?I looked at that exact problem recently and didn't do a complete design, but it looks pretty easy to me.>> The one that failed was made by who? > > It wasn't marked. It lasted almost thirty years bolted onto an automobile's > radiator bracket, so I have absolutely no complaints. Failed with coil open.There seems to be a standard socket for the relays that fit in the boxes in a car. But the relays are slightly different sizes, especially the height. I was looking at inserting a wireless connection in a relay package to allow the motor to be killed without cutting into the wiring. -- Rick
Reply by ●October 4, 20152015-10-04
On Saturday, October 3, 2015 at 2:09:48 PM UTC-4, dagmarg...@yahoo.com wrote:> 12v automotive SSR, to replace a failed $35 unit in my car. > > Q3 > | |-------+---O > | |<-. | > D2 .---+-------+---' |--+ .---' > .-----. | |C1 | | / \ TVS > .--------------------|~ +|--' |10nF .-. R4 | --- > | T1b 500uH | | --- | | 22K | | > '-----. . . . .------|~ -|--. --- '-' | | > '-'-'-'-' '-----' | | | | | > --------- '---+-------+--------+----+---O > --------- > .-.-.-.-. > .------' ' | ' '-------. > | T1a| 1mH | > | | | > O--------+----+----. | > | | | | > | .-. .-. | > | R1 | | R2 | | | > |10K | | 10K | | | > | '-' '-' | > | | ===== | | > \| | .-.-. | |/ > |---+--' ' '--+----| > .<| T1c |>. > | Q1 10uH Q2 | > | | > '----------+-----------' > | > .-. > | | R3 > | | 470 > '-' > | > | > LED1 V ~~> > --- > | > | > V D1 > --- > | > O------------' > > Cheers, > James Arthur > ---- > > Version 4 > SHEET 1 984 680 > WIRE 880 -144 816 -144 > WIRE 352 -64 208 -64 > WIRE 368 -64 352 -64 > WIRE 464 -64 432 -64 > WIRE 656 -64 464 -64 > WIRE 704 -64 656 -64 > WIRE 768 -64 704 -64 > WIRE 352 -48 352 -64 > WIRE 464 -48 464 -64 > WIRE 656 -48 656 -64 > WIRE 704 -48 704 -64 > WIRE 880 -48 880 -144 > WIRE 880 -48 816 -48 > WIRE 208 32 208 -64 > WIRE 352 32 352 16 > WIRE 352 32 288 32 > WIRE 368 32 352 32 > WIRE 464 32 464 16 > WIRE 464 32 432 32 > WIRE 816 48 816 -48 > WIRE 464 64 464 32 > WIRE 656 64 656 16 > WIRE 704 64 704 32 > WIRE 160 128 80 128 > WIRE 256 128 240 128 > WIRE 272 128 256 128 > WIRE 416 128 352 128 > WIRE -176 176 -224 176 > WIRE -48 176 -112 176 > WIRE 176 176 16 176 > WIRE 256 176 256 128 > WIRE 256 176 176 176 > WIRE 320 176 256 176 > WIRE 176 208 176 176 > WIRE 320 208 320 176 > WIRE -224 224 -224 176 > WIRE 80 256 80 128 > WIRE 416 256 416 128 > WIRE 176 304 176 288 > WIRE 176 304 144 304 > WIRE 208 304 176 304 > WIRE 320 304 320 288 > WIRE 320 304 288 304 > WIRE 352 304 320 304 > WIRE -224 336 -224 304 > WIRE 80 384 80 352 > WIRE 256 384 80 384 > WIRE 416 384 416 352 > WIRE 416 384 256 384 > WIRE 256 400 256 384 > WIRE 256 496 256 480 > FLAG 256 496 0 > FLAG -224 336 0 > FLAG 464 64 0 > FLAG 656 64 0 > FLAG 704 64 0 > FLAG 816 48 0 > SYMBOL ind2 144 144 R270 > WINDOW 0 32 56 VTop 2 > WINDOW 3 5 56 VBottom 2 > SYMATTR InstName L1 > SYMATTR Value 500�H > SYMATTR Type ind > SYMBOL ind2 256 144 R270 > WINDOW 0 32 56 VTop 2 > WINDOW 3 5 56 VBottom 2 > SYMATTR InstName L2 > SYMATTR Value 500�H > SYMATTR Type ind > SYMBOL ind2 304 16 R90 > WINDOW 0 5 56 VBottom 2 > WINDOW 3 32 56 VTop 2 > SYMATTR InstName L3 > SYMATTR Value 500�H > SYMATTR Type ind > SYMBOL npn 352 256 R0 > SYMATTR InstName Q1 > SYMATTR Value 2N3904 > SYMBOL npn 144 256 M0 > SYMATTR InstName Q2 > SYMATTR Value 2N3904 > SYMBOL res 160 192 R0 > SYMATTR InstName R1 > SYMATTR Value 10K > SYMBOL res 240 384 R0 > SYMATTR InstName R2 > SYMATTR Value 470 > SYMBOL ind2 304 288 R90 > WINDOW 0 5 56 VBottom 2 > WINDOW 3 32 56 VTop 2 > SYMATTR InstName L4 > SYMATTR Value 10�H > SYMATTR Type ind > SYMBOL res 304 192 R0 > SYMATTR InstName R3 > SYMATTR Value 10K > SYMBOL voltage -224 208 R0 > WINDOW 123 0 0 Left 2 > WINDOW 39 0 0 Left 2 > SYMATTR InstName V1 > SYMATTR Value PULSE(0 12 0 0 0 5mS) > SYMBOL diode 368 -48 R270 > WINDOW 0 32 32 VTop 2 > WINDOW 3 0 32 VBottom 2 > SYMATTR InstName D1 > SYMATTR Value 1N4148 > SYMBOL nmos 768 -144 R0 > SYMATTR InstName M1 > SYMATTR Value AP9465GEM > SYMBOL cap 640 -48 R0 > WINDOW 0 -38 41 Left 2 > WINDOW 3 -33 66 Left 2 > SYMATTR InstName C1 > SYMATTR Value 10nF > SYMBOL res 688 -64 R0 > SYMATTR InstName R4 > SYMATTR Value 22k > SYMBOL diode 432 16 R90 > WINDOW 0 0 32 VBottom 2 > WINDOW 3 32 32 VTop 2 > SYMATTR InstName D2 > SYMATTR Value 1N4148 > SYMBOL diode 368 16 R180 > WINDOW 0 24 64 Left 2 > WINDOW 3 24 0 Left 2 > SYMATTR InstName D3 > SYMATTR Value 1N4148 > SYMBOL diode 480 16 R180 > WINDOW 0 24 64 Left 2 > WINDOW 3 24 0 Left 2 > SYMATTR InstName D4 > SYMATTR Value 1N4148 > SYMBOL LED -176 192 R270 > WINDOW 0 32 32 VTop 2 > WINDOW 3 0 32 VBottom 2 > SYMATTR InstName D5 > SYMATTR Value QTLP690C > SYMATTR Description Diode > SYMATTR Type diode > SYMBOL diode -48 192 R270 > WINDOW 0 32 32 VTop 2 > WINDOW 3 0 32 VBottom 2 > SYMATTR InstName D6 > SYMATTR Value 1N4148 > TEXT 512 240 Left 2 !K1 L1 L2 L3 L4 1. > TEXT 536 296 Left 2 !.tran 10mS > TEXT 520 168 Left 2 ;29-Sep-2015 by jdaThat's not an SSR.
Reply by ●October 5, 20152015-10-05
dagmargoodboat@yahoo.com wrote:> IRL I swapped in a spare from a now-unused accessory.The real low-dough fix is about a 3" piece of 12 gauge wire with two 1/4" push-on terminals crimped on to it, to plug in where the contacts were. Don't forget to unplug it when you park the car, though. :) If it's something that can't stand to run all the time, put a two- terminal turn signal flasher where the contacts were. The duty cycle is approximately 50% but will vary with load, temperature, moon phase, etc.> The radiator cooling fan is the one that failed. The swapped-relay > works, but I won't know until summer if the temp sensor driving its > coil is good. :-)If it's the "standard" automotive relay that comes in about a 1" cube with four or five 1/4" push-on tabs on the bottom, you may be able to get a "generic" one for $10 or so at the car parts store, or possibly at a car stereo and alarm store. Sometimes the car parts people call this a "Bosch relay", and I think Bosch originally came up with the package, but they are now made by many other companies. Like everything else, name-brand ones work well and cheap Chinese ones work for a while. The four-terminal ones are SPST, and *most* of the five-terminal ones are SPDT. *Some* of the five-terminal ones are SPST, with two terminals for one side of the contacts. These get used for things like fog lights, where you want to power two things from the relay contacts, and don't like splices for some reason. The terminals are almost always numbered with the Bosch numbering system. 85 and 86 are the coil. 30 is the "battery" or "feed" side of the contacts. 87 is the NO contact and 87a (if present) is the NC. You can get them with or without a mounting tab. Usually they are rated 30 A but some are rated for more. If they are over 30 A, the coil terminals tend to bigger than 1/4" push-ons. When they first started, the coil was just a coil. After computers in cars happened, the relays grew diodes or resistors across their coils, to help get rid of the spike at switch-off. 12 V is the most common coil voltage but you can get 24 V. Digi-Key has Potter and Brumfield VF4 series, Omron G8JN series, and Panasonic CB series relays like this, for about $3 to $9 quantity one. There are some other "standards". There is one that is about 1" x 1" x 0.5", with more closely-spaced 1/4" push-on terminals on the bottom. Some Japanese cars have relays that have two rows of up to three push- ons each in a "connector housing" that is part of the relay body. Digi-Key also has some of those, but not as much selection as the 1" cube ones. Standard disclaimers apply: I don't get money or other consideration from any companies mentioned. Matt Roberds
Reply by ●October 5, 20152015-10-05
On 2015-10-04, tabbypurr@gmail.com <tabbypurr@gmail.com> wrote:> On Sunday, 4 October 2015 00:02:59 UTC+1, dagmarg...@yahoo.com wrote: > >> The radiator cooling fan is the one that failed. The swapped-relay works, but I >> won't know until summer if the temp sensor driving its coil is good. :-) >> >> Cheers, >> James > > In many places cars are fine with a permanently dead rad fan.It took me two summers to figure out why my car would boil sometimes. Dead fan motor: disection revealed EMI supression choke separated from brush carrier board I fitted a generic fan (20% of the price of genuine), and now the AC works better too. -- \_(ツ)_
Reply by ●October 5, 20152015-10-05
Tom Miller wrote:> Since speed is not an issue, a 555 and a few capacitors in a doubler > would work to drive the Mosfet.Or IR2153 with its HO and LO ouput stages driving a tiny transformer directly, in the full bridge configuration. Just 3 parts and allows multiple isolated output voltages if needed. Unfortunately, I didn't invent it. ;-) Best regards, Piotr
Reply by ●October 5, 20152015-10-05
Den mandag den 5. oktober 2015 kl. 11.48.41 UTC+2 skrev Piotr Wyderski:> Tom Miller wrote: > > > Since speed is not an issue, a 555 and a few capacitors in a doubler > > would work to drive the Mosfet. > > Or IR2153 with its HO and LO ouput stages driving a tiny > transformer directly, in the full bridge configuration. > Just 3 parts and allows multiple isolated output voltages > if needed. Unfortunately, I didn't invent it. ;-) > > Best regards, PiotrAUIR2085S is higher current and higher speed +/-1A, 500KHz -Lasse
Reply by ●October 5, 20152015-10-05
On Monday, October 5, 2015 at 1:28:16 AM UTC-4, mrob...@att.net wrote:> dagmargoodboat@yahoo.com wrote: > > IRL I swapped in a spare from a now-unused accessory. > > The real low-dough fix is about a 3" piece of 12 gauge wire with two > 1/4" push-on terminals crimped on to it, to plug in where the contacts > were. Don't forget to unplug it when you park the car, though. :) > > If it's something that can't stand to run all the time, put a two- > terminal turn signal flasher where the contacts were. The duty cycle > is approximately 50% but will vary with load, temperature, moon phase, > etc. > > > The radiator cooling fan is the one that failed. The swapped-relay > > works, but I won't know until summer if the temp sensor driving its > > coil is good. :-) > > If it's the "standard" automotive relay that comes in about a 1" cube > with four or five 1/4" push-on tabs on the bottom, you may be able to > get a "generic" one for $10 or so at the car parts store, or possibly > at a car stereo and alarm store. Sometimes the car parts people call > this a "Bosch relay", and I think Bosch originally came up with the > package, but they are now made by many other companies. Like everything > else, name-brand ones work well and cheap Chinese ones work for a while. > > The four-terminal ones are SPST, and *most* of the five-terminal ones > are SPDT. *Some* of the five-terminal ones are SPST, with two terminals > for one side of the contacts. These get used for things like fog > lights, where you want to power two things from the relay contacts, and > don't like splices for some reason. > > The terminals are almost always numbered with the Bosch numbering > system. 85 and 86 are the coil. 30 is the "battery" or "feed" side > of the contacts. 87 is the NO contact and 87a (if present) is the NC. > > You can get them with or without a mounting tab. Usually they are > rated 30 A but some are rated for more. If they are over 30 A, the > coil terminals tend to bigger than 1/4" push-ons. > > When they first started, the coil was just a coil. After computers in > cars happened, the relays grew diodes or resistors across their coils, > to help get rid of the spike at switch-off. 12 V is the most common > coil voltage but you can get 24 V. > > Digi-Key has Potter and Brumfield VF4 series, Omron G8JN series, and > Panasonic CB series relays like this, for about $3 to $9 quantity one. > > There are some other "standards". There is one that is about 1" x 1" > x 0.5", with more closely-spaced 1/4" push-on terminals on the bottom. > Some Japanese cars have relays that have two rows of up to three push- > ons each in a "connector housing" that is part of the relay body. > Digi-Key also has some of those, but not as much selection as the 1" > cube ones. > > Standard disclaimers apply: I don't get money or other consideration > from any companies mentioned. > > Matt RoberdsThanks Matt. It's approximately a Bosch format with a mounting tab, but half the standard thickness. Electronic Goldmine and BG Micro have the standard Bosch format for about $1.50. My fallback is to get one of those and kludge a wiring harness to mate the replacement to fit the original connector. Cheers, James Arthur
Reply by ●October 6, 20152015-10-06
dagmargoodboat@yahoo.com wrote:> It's approximately a Bosch format with a mounting tab, but half the > standard thickness.If the terminals are 1/4", maybe something like: http://www.digikey.com/product-detail/en/CM1A-R-12V/255-3729-ND/647140 http://www.digikey.com/product-detail/en/G8HN-1C2T-R%20DC12/Z2247-ND/765512 http://www.digikey.com/product-detail/en/VFMA-15F41-S01/VFMA-15F41-S01-ND/1210025 If the terminals are tiny, maybe something like http://www.digikey.com/product-detail/en/G8V-1C7T-R-DC12/Z2052-ND/369439 http://www.digikey.com/product-detail/en/G8V-RH-1A7T-R-DC12/Z2648-ND/1506402 I haven't seen any of these "half size" ones with a mounting tab... it seems like they came out after all the relays got moved to a central relay box. I'm sure an automaker can get them that way, but I don't know if humans can get them in quantity 1.> Electronic Goldmine and BG Micro have the standard Bosch format for > about $1.50. My fallback is to get one of those and kludge a wiring > harness to mate the replacement to fit the original connector.Digi-Key sells the sockets to go with the Bosch relays, but they come as a housing and loose crimp terminals. Sometimes it's easier to get something like this http://www.delcity.net/store/Pre!Wired-Relay-Socket-Harness/p_72562 with a foot of wire already on it. The local car alarm shop will definitely have these kinds of sockets in stock. Standard disclaimers apply: I don't get money or other consideration from any companies mentioned. Matt Roberds
Reply by ●October 8, 20152015-10-08
John Larkin <jjlarkin@highlandtechnology.com> writes:> On Sat, 3 Oct 2015 20:42:59 -0400, "Tom Miller" > <tmiller11147@verizon.net> wrote: > >> >>"rickman" <gnuarm@gmail.com> wrote in message >>news:mupjij$k5a$1@dont-email.me... >>> On 10/3/2015 5:57 PM, Tom Miller wrote: >>>> >>>> "rickman" <gnuarm@gmail.com> wrote in message >>>> news:muph5o$88r$2@dont-email.me... >>>>> On 10/3/2015 4:58 PM, John Larkin wrote: >>>>>> On Sat, 3 Oct 2015 11:09:40 -0700 (PDT), dagmargoodboat@yahoo.com >>>>>> wrote: >>>>>> >>>>>> >>>>>> PV optocouplers are cool for driving isolated gates, but maybe not >>>>>> available in your junk box. >>>>>> >>>>>> I'm designing a kilovolt-range linear voltage regulator, and a PV is a >>>>>> really easy way to drive the pass transistor gate. >>>>>> >>>>>> Hey, a packaged SIP dc/dc converter would make a nice SSR gate driver. >>>>>> $4 or something from Mouser. >>>>> >>>>> That is the point of this circuit. A PV photocoupler needs a power >>>>> source. This circuit *is* the power source. >>>>> >>>>> >>>> >>>> No, a PV optocoupler makes it own voltage. Just add it to the 12 volts >>>> to drive the gate. >>> >>> Since when? They use a phototransistor, not a PV solar cell. >>> >>> -- >>> >>> Rick >> >>I guess that's why they call them PV optocouplers. > > A phototransistor optocoupler will generate a little voltage on the > output side, not enough to be useful for anything I can imagine.Maybe the trick of generating a negative bias current to pull an opamp output down though ground? -- John Devereux
