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Timer baseball feeder circuit

I have a 3v dc motor that turns at a slow rpm. It has a rubber wheel that comes in contact with a baseball. This allows the baseball to be pushed in to a pitching machine. The ball waits in line to be driven by the motor. I would like to be able to turn the motor on but have a time delay of approximately 15 sec before it runs continuously. I will have a limit switch to turn off the motor after the last ball has been pitched. What type of circuit would be needed to produce this? I know this is pretty basic but I=92m very new to this. I can read schematics, build circuits and have experience with electronic components but having the proper circuit would make things very easy for me. Can some one make a schematic that I can use to accomplish this? Any information would greatly be appreciated. Thank you in advance for your time.

Dave K

Reply to
DaveK
Loading thread data ...

--
If you only have 3V available to do everything, this should work.
(View in Courier)

The timer is a CMOS 555, and if you can tell us how much current the
motor draws, one of us can select an appropriate MOSFET for Q1.

                                                ____ 
.        | -----O S1    |     |      8|       |  [1N4001] [MOTOR]
.             [100K] [1M]  +---+---+   |     |        |
.                |     |  2|_ Vcc _|4  |     +--------+
.                +-----|--O|T     R|O--+     |
.                |     |  6|       |   |     D
.                |     +---|TH  OUT|---|---G NCH
.                |     |  7|_      |3  |     S Q1
.             [100nF]  +--O|D  7555|   |     |
.                |    +|   |  GND  | [10K]   |
.                |  [10µf] +---+---+   |     |
.                |     |      1|       |     |
.GND>------------+-----+-------+-------+-----+

JF
Reply to
John Fields 

--
Aaarghhh!!!

Jumped the gun on that one, sorry...

This one\'s right, I think.  

S1 is the motor ON switch and S2 is the motor\'s limit switch, assuming
it\'s normally closed while the motor\'s running.


.     | --O S1    |     |      8|       |   |    |            
.          [100K] [1M]  +---+---+   | [10k]  |            
.             |     |  2|_ Vcc _|4  |   |    |             
.             +-----|--O|T     R|O--+   |    |
.             |     |  6|       |   |   |    S
.             |     +---|TH  OUT|---|---+--G PCH
.             |     |  7|_      |3  |        D Q1
.          [100nF]  +--O|D  7555|   |        |  ____
.             |    +|   |  GND  | [10K]      +--O  O--+
.             |  [10µf] +---+---+   |        |K  S2   |
.             |     |      1|       |    [1N4001]  [MOTOR]
.             |     |       |       |        |        |
.GND>---------+-----+-------+-------+--------+--------+

The way it works is that as soon as S1 is made, the timer will output
a 15 second high-going pulse which will keep Q1 turned off.

Then, if S2 is made when the timer times out and pulls the gate of Q1
low, Q1 will switch on and allow charge to flow through the motor
until S2 opens.

When that happens, you\'ll need to open S1 before you load more balls
into the machine and override the limit switch.

Then, after the balls are loaded, to start the cycle anew, just turn
S1 ON. 

About 15 seconds later it should start spitting out balls again. :-)

JF
Reply to
John Fields

a

=A0 =A0 =A0 =A0 =A0 =A0____

=A0 =A0 |K =A0S2 =A0 |

[MOTOR]

=A0 =A0 =A0|

+--------+

=A0 =A0 D

=A0 =A0 S Q1

|

=A0 =A0 |

=A0| =A0 =A0 =A0 =A0 =A0

=A0 =A0 =A0 =A0 =A0 =A0

=A0 =A0 =A0 =A0

=A0 =A0 =A0 =A0 =A0 =A0

=A0S

=A0 =A0D Q1

=A0____

+--O =A0O--+

=A0S2 =A0 |

[1N4001] =A0[MOTOR]

=A0 =A0| =A0 =A0 =A0 =A0|

JF,

Thank you so much for you response. There is nothing on the motor indicating amp draw. It has many gears to deliver high torque which I think lower the amp draw. The transformer puts out 3vdc at 500ma. I hope that is enough info to pick out the correct MOSFET.

I took your schematic into WORD and used "courier new" because for some reason plain courier was not an option, so in-turn the schematic looks just like the one on this page. I have used schematics that were sent to me awhile back and they worked out great in WORD. I must have had the option of using courier instead of courier new.

I believed I could figure something out one way or another, unless you have any suggestions. The way it is now I=92m just not smart enough to decipher it totally.

Thanks again for your prompt response

Reply to
DaveK 

--
You\'re welcome.

The schematic is just an ASCII representation of a graphic schematic.

Perhaps this\'ll help:

.     | --O S1    |R1   |R2    8|       |   |R4  |            
.          [100K] [1M]  +---+---+   | [10k]  |            
.             |     |  2|_ Vcc _|4  |   |    |            
.             +-----|--O|T     R|O--+   |    |
.             |     |  6|       |   |   |    S
.             |     +---|TH  OUT|---|---+--G FDP4020P
.             |C1   |  7|_      |3  |        D Q1
.          [100nF]  +--O|D      |   |R3      |  ____
.             |    +|   |  GND  | [10K]      +--O  O--+
.             |  [10µf] +---+---+   |        |K  S2   |
.             |     |C2    1| U1    |    [1N4001]  [MOTOR]
.             |     |       | 7555  |      D1|        |
.GND>---------+-----+-------+-------+--------+--------+


JF
Reply to
John Fields

A Fairchild FDC604P is a better choice for Q1:

formatting link

.     | --O S1    |R1   |R2    8|       |   |R4  |             .          [100K] [1M]  +---+---+   | [10k]  |             .             |     |  2|_ Vcc _|4  |   |    |             .             +-----|--O|T     R|O--+   |    | .             |     |  6|       |   |   |    S .             |     +---|TH  OUT|---|---+--G FDC604P .             |C1   |  7|_      |3  |        D Q1 .          [100nF]  +--O|D   |   |R3      |  ____ .             |    +|   |  GND  | [10K]      +--O  O--+ .             |  [10µf] +---+---+   |        |K  S2   | .             |     |C2    1| U1    |    [1N4001]  [MOTOR] .             |     |       | 7555  |      D1|        | .GND>---------+-----+-------+-------+--------+--------+

--- If you want to see how it works you can get a free copy of LTspice from:

formatting link

and run this:

Version 4 SHEET 1 880 864 WIRE -304 160 -544 160 WIRE -224 160 -304 160 WIRE -128 160 -224 160 WIRE -16 160 -128 160 WIRE 352 160 -16 160 WIRE 448 160 352 160 WIRE -224 192 -224 160 WIRE -128 192 -128 160 WIRE 448 192 448 160 WIRE -544 208 -544 160 WIRE -592 224 -720 224 WIRE 96 240 48 240 WIRE 352 240 352 160 WIRE 352 240 320 240 WIRE -128 304 -128 272 WIRE 96 304 -128 304 WIRE 448 304 448 272 WIRE 448 304 320 304 WIRE -304 352 -304 160 WIRE -224 368 -224 272 WIRE -224 368 -256 368 WIRE 96 368 -224 368 WIRE 448 368 448 304 WIRE 448 368 320 368 WIRE -16 432 -16 160 WIRE 96 432 -16 432 WIRE -304 464 -304 448 WIRE -304 464 -400 464 WIRE -128 464 -128 304 WIRE 352 464 352 240 WIRE 448 464 448 368 WIRE -720 480 -720 224 WIRE -544 480 -544 288 WIRE -16 480 -16 432 WIRE -304 512 -304 464 WIRE -400 528 -400 464 WIRE -720 624 -720 560 WIRE -592 624 -592 272 WIRE -592 624 -720 624 WIRE -544 624 -544 560 WIRE -544 624 -592 624 WIRE -400 624 -400 592 WIRE -400 624 -544 624 WIRE -304 624 -304 592 WIRE -304 624 -400 624 WIRE -128 624 -128 528 WIRE -128 624 -304 624 WIRE -16 624 -16 560 WIRE -16 624 -128 624 WIRE 48 624 48 240 WIRE 48 624 -16 624 WIRE 352 624 352 528 WIRE 352 624 48 624 WIRE 448 624 448 528 WIRE 448 624 352 624 WIRE -720 704 -720 624 FLAG -720 704 0 SYMBOL Misc\\\\NE555 208 336 R0 SYMATTR InstName U2 SYMBOL cap 432 464 R0 SYMATTR InstName C1 SYMATTR Value 10e-6 SYMBOL diode -384 592 R180 WINDOW 0 24 72 Left 0 WINDOW 3 24 0 Left 0 SYMATTR InstName D1 SYMATTR Value 1N4148 SYMBOL pmos -256 448 R180 SYMATTR InstName M1 SYMATTR Value FDC638P SYMBOL res 432 176 R0 SYMATTR InstName R2 SYMATTR Value 1e6 SYMBOL res -144 176 R0 SYMATTR InstName R4 SYMATTR Value 100k SYMBOL cap -144 464 R0 SYMATTR InstName C2 SYMATTR Value 100e-9 SYMBOL voltage -544 464 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value 3 SYMBOL voltage -720 464 R0 WINDOW 0 -53 5 Left 0 WINDOW 3 -242 110 Invisible 0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V2 SYMATTR Value PULSE(0 1 .1 1E-6 1E-6) SYMBOL sw -544 304 M180 WINDOW 0 32 15 Left 0 WINDOW 3 32 44 Left 0 SYMATTR InstName S1 SYMBOL res -32 464 R0 SYMATTR InstName R1 SYMATTR Value 10k SYMBOL cap 336 464 R0 SYMATTR InstName C3 SYMATTR Value 100e-9 SYMBOL res -240 176 R0 SYMATTR InstName R5 SYMATTR Value 10k SYMBOL ind -320 496 R0 SYMATTR InstName L1 SYMATTR Value .1 SYMATTR SpiceLine Rser=6 TEXT -688 648 Left 0 !.tran 20 TEXT -688 680 Left 0 !.model SW SW(Ron=1 Roff=10Meg Vt=0.5Vh=0)

JF

Reply to
John Fields

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