E
ehsjr
Guest
kayvee wrote:
Here's another one:
http://www.datasheetcatalog.com/datasheets_pdf/P/M/D/1/PMD16K100.shtml
Since the datasheet calls it an NPN, what is the proof that
it is a PNP? That discrepancy really needs to be cleared
up so that you can get the correct circuit.
Ed
Paul posted references to urls that call the PMD16K100 an NPN.On Nov 25, 6:59 pm, Jamie
jamie_ka1lpa_not_valid_after_ka1l...@charter.net> wrote:
Sjouke Burry wrote:
kielvereec...@gmail.com wrote:
On Nov 25, 5:03 pm, "Paul E. Schoen" <pst...@smart.net> wrote:
"kayvee" <kmvgro...@gmail.com> wrote in message
news:88fbbd1b-04fd-4a85-bcac-e70207cd7960@d32g2000yqe.googlegroups.com...
On Nov 25, 12:06 pm, "Bob Monsen" <robertmon...@sbcglobal.net> wrote:
"kayvee" <kmvgro...@gmail.com> wrote in message
news:80a38d0c-8ab7-4dc1-8cc0-eda7cfe0d6b9@x14g2000yqk.googlegroups.com...
I was planning on using a darlington pair for this project...
Your transistor is already a darlington transistor, meaning the two
transistors is built into it, so use ehsjr's circuit, and you'll be
fine.
Regards,
Bob Monsen
oh perfect! Will my 10k pot still be fine?
=======================================================
10k pot is fine, and really the 4.7 k base resistor is not necessary
for an
emitter follower.
You will only be able to get about 22.5 volts from a 24 VDC supply
with a
darlington.
You can get a bit more by using
ahttp://en.wikipedia.org/wiki/Sziklai_pair, as in the following LTspice
circuit, but you need to put the motor (simulated by a resistor and
inductor) from the positive rail to the collector of the NPN, or use a
power PNP transistor with NPN driver.
I set up a programmed voltage source and 5k resistor to simulate the
pot,
and it shows the inductive kick from the motor when it is turned off
quickly. A real motor will also exhibit back EMF due to its action as a
generator as it coasts to a stop.
Paul
=======================================================
Version 4
SHEET 1 880 680
WIRE 352 -128 32 -128
WIRE 448 -128 352 -128
WIRE 448 -64 448 -128
WIRE 352 -32 352 -48
WIRE 352 64 352 48
WIRE 448 64 448 0
WIRE 448 64 352 64
WIRE 352 96 352 64
WIRE 352 96 256 96
WIRE 32 128 32 -128
WIRE 192 144 160 144
WIRE 160 176 160 144
WIRE 352 176 352 96
WIRE 256 224 256 192
WIRE 288 224 256 224
WIRE 160 288 160 256
WIRE 32 432 32 208
WIRE 160 432 160 368
WIRE 160 432 32 432
WIRE 352 432 352 272
WIRE 352 432 160 432
WIRE 32 448 32 432
FLAG 32 448 0
SYMBOL voltage 32 112 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 24
SYMBOL pnp 192 192 M180
SYMATTR InstName Q1
SYMATTR Value 2N3906
SYMBOL npn 288 176 R0
SYMATTR InstName Q2
SYMATTR Value 2N3055
SYMBOL res 336 -144 R0
SYMATTR InstName R1
SYMATTR Value 50
SYMBOL diode 464 0 R180
WINDOW 0 -25 64 Left 0
WINDOW 3 -99 0 Left 0
SYMATTR InstName D1
SYMATTR Value MURS120
SYMBOL ind 336 -48 R0
SYMATTR InstName L1
SYMATTR Value 100m
SYMBOL voltage 160 272 R0
WINDOW 3 -95 138 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value PWL(0 24 0.1 0 0.9 0 0.901 24)
SYMBOL res 144 160 R0
SYMATTR InstName R2
SYMATTR Value 5k
TEXT -2 472 Left 0 !.tran 1 startup
Actually, a Sziklai pair might be the best for me, because the
PMD16K100 I snagged turns out to be a PNP transistor, rather than a
NPN, which a assumed it was.
Now would I hook it up like this?
24V------o----------------.
| |
| |/
| o------| PMD16K100 (PNP)
| | |
| | |
.-. |/ |
10k | |<---| 2N4401 |
| | |> |
'-' | |
| | |
| '--------o
| |
| .--------o
| | |
| | .---o----.
| - | |
| ^ | motor |
| 1N4001 | |
| | '---o----'
| | |
| | |
GND--------o-------o--------'
A pnp transistor with the colle3ctor to the + side? No way.
Stick to one npn darlington instead.
Actually, you can use the PNP, it's just upside down.
the emitter needs to go to the (+).
This configuration works well with in a 0.7 V window of
regulation.
http://webpages.charter.net/jamie_5"
So Jamie, this looks better:
24V------o----------------.
| |
| |
| o------| PMD16K100 (PNP)
| | |\
| | |
.-. |/ |
10k | |<---| 2N4401 |
| | |> |
'-' | |
| | |
| '--------o
| |
| .--------o
| | |
| | .---o----.
| - | |
| ^ | motor |
| 1N4001 | |
| | '---o----'
| | |
| | |
GND--------o-------o--------'
Here's another one:
http://www.datasheetcatalog.com/datasheets_pdf/P/M/D/1/PMD16K100.shtml
Since the datasheet calls it an NPN, what is the proof that
it is a PNP? That discrepancy really needs to be cleared
up so that you can get the correct circuit.
Ed