logic gate equivalent circuit of a bosch relay?

Discussion in 'General Electronics Chat' started by 03GTS, Mar 23, 2007.

  1. 03GTS

    Thread Starter Member

    Jan 5, 2007
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    anyone know of one?
     
  2. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    The Bosh is what we call a "form C" relay or "Single Pole Double Throw" relay.

    One can make logic gates from relays. Making a relay from a logic gate would be sort of like making a coldcut from a sandwich.

    Are you perhaps looking for a solid state relay?
     
  3. 03GTS

    Thread Starter Member

    Jan 5, 2007
    12
    0

    well what i am doing is making sequential turn signals. the problem is if i have the parking/running lights on and i turn my turn signal on that the leds need flash and not just stay on as running lights.

    having problem cordinating both :)

    solid state relays are expensive i am hoping i dont have to go that route :(
     
  4. thingmaker3

    Retired Moderator

    May 16, 2005
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    :confused:

    Okay. Where does the Bosh relay equivalent come in?
     
  5. 03GTS

    Thread Starter Member

    Jan 5, 2007
    12
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    dont think this could work?

    [​IMG]
     
  6. wireaddict

    Senior Member

    Nov 1, 2006
    133
    0
    This doesn't show the internal workings of the relay. A "C" form relay has one or more sets of contacts, each set with three terminals, a normally open [NO] & a normally closed [NC] contact wired in series with a common terminal connected to the junction between them. My guess is that wires #85 & 86 are the coil leads, wire #30 goes to the common, #87a to the NC & #87 to the NO contact.

    I'm not familiar with the wiring on newer cars but the older ones had bulbs with two filaments or more than one bulb, one for the parking/running lights & the other, brighter one for turn signals & brake lights [on the rear]. Hopefully you have two sets of LEDs or have the space to add them.

    As for operating the sequential turn signals you can use either a stepping relay or a shift register & LED driver transistors. To save some time & money you might cruise a few auto salvage yards & see what's there.
     
  7. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
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    Schematic of the Bosch relay as used in this application:
    bosch seq lights.jpg

    Schematic of solid state circuit which should accomplish same thing:
    mosfet seq lights sch.jpg
    Select Q1 and Q2 to handle not less than 120% of the expected current and not less than 120% of B+.

    Select R2 and R4 as not less than (120% of B+ voltage divided by 0.8 Amps.)

    Select R1 and R2 as not less than (120% of "Turn Signal Active" voltage divided by 0.2 Amps.)
     
  8. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
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    Disregard this post
     
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