Alt-BEAM Archive
Message #11848
To: beam@sgiblab.sgi.com
From: BUDSCOTT@aol.com
Date: Tue, 14 Mar 2000 22:17:42 EST
Subject: [alt-beam] Re: Turbots
OOO! lotus, alittle off topic but a sweet car!
-Spencer
11849 Wed, 15 Mar 2000 14:33:46 +1100 (EST) [alt-beam] Re: H-Bridge beam@sgiblab.sgi.com Ben Hitchcock Take two NPN transistors, and connect their emitters to ground.
Take two PNP transistors, and tie their emitters to +Vcc.
Connect the collector of NPN1 to the collector of PNP1, and attach the
positive terminal of your motor here.
Connect the collector of NPN2 to the collector of PNP2,
and attach the negative terminal of the motor to that point also.
Now attach 1k resistors to all the four base terminals.
Connect NPN1 and PNP1 via their base resistors. Where the two resistors
join, call this bias point 1.
Connect NPN2 and PNP2 via their base resistors. Where the two resistors
join, call this bias point 2.
Now treat bias point 1 and bias point 2 as a motor. Both high or both low
and nothing happens. one high and 2 low, it spins one way, but reverses
if you swap polarities.
Note that this should ONLY be driven by logic gates, not analog circuitry
because if the bias points are halfway between the supply rails then you
will let the smoke out.
+v-------o-----------------o----
| |
P P
+-1k-n n--1k-+
| p p |
| | | |
BP1o o-----Motor-------o o Bias Point 2
| | | |
| n n |
+-1k-p p--1k-+
N N
| |
0V-------o-----------------o---
> I seem to be having trouble with a smokless non latching H-bridge
> everything i have tried resulted in either a latching H-Bridge or
> when both inputs were pulled either high or low the bridge would
> short :(
>
> Any thoughts?
>
> I was trying out W.Rigter's Smokless latching 4 transistor H-Bridge
> and remover the 2 resistors that supply the latching current but for
> some reason that did not work either :(
>
> Regards
> Andrew
>
--
Nothing is foolproof to a sufficiently talented fool.
11850 Tue, 14 Mar 2000 23:27:35 EST [alt-beam] power smart head beam@corp.sgi.com Bumper314@aol.com Hello,
I am looking for the original power smart head circuit that wilf posted.
Anyone have it?
steve
11851 Tue, 14 Mar 2000 20:29:49 -0800 (PST) [alt-beam] Photodiodes BEAM List Daniel Grace I feel horrible mailing the list so much, but from
what can photodiodes be salvaged from? I dispise mail
order, and was really hoping I could get these from a
local store (checked, and no such luck) or from some
device (which is what I need your help for). I'd much
rather drive through all the garage sales and salvage
a lot of components from a small $2 thing than mail
order it and pay more than it's worth in shipping and
handling.
~Daniel
=====
ICQ # 39402143
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11852 Tue, 14 Mar 2000 19:56:04 -0800 (PST) [alt-beam] Capacitor Values - Complete BEAM List Daniel Grace I sent an e-mail earlier, but now I have all the
capacitors straightened out. Here are ALL of them.
3300
20%
3300
10%
RMC
.04Z
Z5U
2KV
MDC
4700M
Z5U 2KV
3900
20%
KCK
3 9 J
N/50
.47Z
10V Y5U
MEXICO
.0015
+100%
-0%
39M
24 (underlined)
220
M
22 (underlined)
RMC
150NI50
5%
NPO
56+/-10%
1500
10%
KCK
8 2 J
N150
.001M
Z5P
and now the big one!
-U-
RMC
.005
+80-20
150VAC
1400VDC
Z5U
Of cource, it would be better if you could teach me
how to read all of these, but there seems to be about
20 different conventions in use, so it may be quicker
to just say what each is.
~Daniel
PS. I guess this'll teach me to buy things in
"Assorted" packs.
=====
ICQ # 39402143
__________________________________________________
Do You Yahoo!?
Talk to your friends online with Yahoo! Messenger.
http://im.yahoo.com
11853 Tue, 14 Mar 2000 22:44:20 -0600 [alt-beam] Re: Turbots beam@sgiblab.sgi.com SG At 06:46 PM 3/14/00 -0800, you wrote:
>>
>Sure is,
>
>I used to drive a '78 Lotus (Esprit, S2) . DOHC, 4 banger, dual carbs,
>25MPG/125 MPH, Best handling sports car ever,
nice huh!
Hemmings Motor News still shows some available around the U.S.
still holding out for a VW Karmann Ghia Convertable though. Had my
Sutebaker stolen my first year of Grad school.
*sigh*
-sparky
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