Alt-BEAM Archive

Message #07518

JVernonM@aol.com wrote:

In a message dated 11/10/99 3:32:31 PM Eastern Stan=
dard
Time,

michael.hirtle@ns.sympatico.ca writes:

> That must be why my magbot and solar roller didn't work, how do i
fix this

>  problem?

>

>  SG wrote:

>

>  > At 03:12 AM 11/10/99 EST, you wrote:

>  > >If your 1F cap is one of the stubby short ones that could
be your

problem.

>

>  > >The caps in the long or "AL" type case have a lower internal

resistance.

> I

>  > >had the same problem.

>  > >See ya,

>  > >Jim

Well, easiest is to replace the cap with an AL case variety. Someone
had

another  fix that was posted on the list some time ago. I don't
remember who

it was (Wilf, Bob, Ben, ??). It involved a buffer cap as I recall.

See ya,

Jim

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7519 Wed, 10 Nov 1999 13:13:37 -0800 [alt-beam] Re: Pots in the head "'beam@sgiblab.sgi.com'" Wilf Rigter Hi Victor,

Good point about naming conventions. When I say pot or potentiometer, I mean
a single or 10 turn screwdriver adjustable "miniature trimpot" (which are
always linear) unless otherwise specified. The 5M single turn units I use
are made by Phillips but I have no part number, they were cheap less than $1
each. The 5M - 10 turn trim pots Bourns Series 3296 from Digikey cost $4
and are easier to fine tune. Alternately use 3.3M fixed resistor in series
with a 1M pot for R1 and R2 with the fixed resistor for R1 at the output of
inverter A. Lowering the R total value of R is not recommended since it
should be high compared to the resistance of the photobridge. You can use a
variety of C values 0.1 - 0.01uf is ok

regards


Wilf Rigter mailto:wilf.rigter@powertech.bc.ca
tel: (604)590-7493
fax: (604)590-3411

> -----Original Message-----
> From: Victor Snesarev [SMTP:snesarev@ecel.ufl.edu]
> Sent: Wednesday, November 10, 1999 10:58 AM
> To: BEAM List
> Subject: Pots in the head
>
> Hi,
>
> After reading Wilf's wonderful tutorial, I decided to build a PS Head.
> Once I started looking for components, though, I found that either a
> 5MEG pot is not easy to come by, or I am looking at all the wrong places
> (DigiKey, All Electronics, ....)
>
> First is a question of naming things. I call a potentiometer a variable
> resistor with a longish nob that can easily be turned with fingers, and
> a trim potentiometer a boxy-looking device (plastic on the
> outside--that's all i've seen) with a tiny screw. Trim pots seem to be
> used in photopopers for example. Am I naming these devices by their
> correct names -- names that a supplier of these parts would use? Oh, and
> then there are tapers, and I think they look more like potentiometers,
> but I am not sure.
>
> DigiKey doesn't have any pots over 2MEG. However, All Electronics has a
> 5MEG linear taper (PC mount pot with 3/16" diameter, half-moon nylon
> shaft. Non-threaded bushing.) PC mount, and 3/16" diameter make me
> believe that it is one of those small deals that would fit nicely on a
> head. Am I wrong?
>
> And the final issue. Since the frequency of the of the HI/LO OSC, and of
> Nv/Nu stage is controlled by the resistance of the pots (R1 & R2) and
> cap. values (C1 & C2), is it feasible to increase the C's, and decrease
> the R's to get the same RC constant and hence frequency? With
> approximate values from the tutorial
>
> RC = 2.5MOhms * 0.01uF = 250KOhms * 0.1uF.
>
> I.e. replace the pots by 500K pots and the caps by 0.1uF caps.
>
> Thanks in advance for any info.
>
> Victor
>
>



7520 Wed, 10 Nov 1999 15:36:43 -0600 [alt-beam] Re: solar head questions.. beam@sgiblab.sgi.com Brad Guillot

Wilf Rigter wrote:
>
> Couple of questions:
>
> a. What head circuit are you using : the 2Nv bicore as discussed in your
> progress report?

that was for expermanting- i moved on to the pshv1 on darell jonson's
page (guess i need an update)
> b. What solar engine?

Doesn't the above circuit have an se built into it???
> c. What is the supply voltage you use during the testing?

2 aa low drain batteries(3v, unknown amps)


> Couple of points:
>
> 1. The 74ALS245 uses about 20ma just by itself: yikes!

that will cut into efficeny

> 2. You can connect the 74ALS245 as shown in the attached.
>
> 3. You get a lot more motor power by raising the "solar" supply voltage.
> ie use a chloroplast SE or use a 1381U
>
> 4. Higher supply voltage requires increased voltage ratings on the solar
> cell, caps or batteries (ie 6V)

Thanks a bunch
brad

ps i did the improvements you saud in the last message and it did the
trick-pluss it got rid of that motor buzzing

>
> Wilf Rigter mailto:wilf.rigter@powertech.bc.ca
> tel: (604)590-7493
> fax: (604)590-3411
>
> > -----Original Message-----
> > From: Brad Guillot [SMTP:mach50@netzero.com]
> > Sent: Tuesday, November 09, 1999 5:07 PM
> > To: beam@sgiblab.sgi.com
> > Subject: Re: solar head questions..
> >
> >
> > Wilf Rigter wrote:
> >
> > > Well I would say, "read the manual" but seriously,
> >
> > I did , it was real late, i probally didn't catch the details
> >
> >
> > > 1.what motor driver?
> > ok. the circuit will directly power a led, for some reason not a
> > pager
> > motor. who woulda knew?(I'm not the only one with this problem)
> > My analog meter tells me its like 20mA output, my pm needs like 40mA
> > and would prefer 80mA or so. so i attached a 245 driver and it works
> > real nice. i was wondering how to connect it to the circuit so it was
> > only on when the motors kick on. I tried like 10 differnt ways and most
> > of the time it made the circuit go haywire. the times it stayed normal,
> > i didn't achice my goal(the driver was still on). i sopose it would just
> > work in parrell withthe solar cell because it doesn't drain that much
> > power when it is not in use, but in solar apps. every little bit helps.
> >
> >
> >
> > > 2.Without the solar circuit ie battery power the light stays on. Darrell
> > > added the FLED to "attract attention" to the solar PShead when it is
> > ready
> > > for action.
> >
> > I am using the solar circuit powerd by a battery. my problem was that
> > when the motor turns, the fled is soupposed to turn off. mine stays lit
> > even when the motor turns. i found a way to make it stop when the motor
> > turns on,(grounding pin 2) but the entire circuti the dies because the
> > fled is attached to the enable/disable pin. Would detaching it from that
> > pin make it work?
> >
> >
> > > 3.That certain component wouldn't be pin 6 and 8 of the HC240? Those
> > should
> > > be connected to 0V (instead of floating as shown on Darrell's layout
> > > drawing. Also make sure you add a small (eg 10uf /10V) electrolytic
> > > capacitor from pin 20 to pin 10. The actual cap value does not matter
> > much
> > > but it should have relatively direct connections with short leads. This
> > > stops high frequency oscillations which upset normal circuit operation.
> >
> > Thank YOU very much!
> > that is very helpful
> >
> > thanks
> > brad
> >
> > > > -----Original Message-----
> > > > From: Brad Guillot [SMTP:mach50@netzero.com]
> > > > Sent: Tuesday, November 09, 1999 3:04 PM
> > > > To: beam@sgiblab.sgi.com
> > > > Subject: solar head questions..
> > > >
> > > >
> > > > These are some questions/ problems a few of us have been having with
> > the
> > > > solar head project. I thought i'd ask.
> > > >
> > > > 1. for use in solar power, Where would you hook up the motor driver?
> > > >
> > > >
> > > > 2. The circuit works but he active circuit indincator light NEVER
> > stops,
> > > > even when it moves. What's up?
> > > >
> > > >
> > > >
> > > > 3.The circuit seems to work right when i move my finger over or touch
> > a
> > > > certian component. Why does it do this and how do we fix it?
> > > >
> > > >
> > > >
> > > > These are some problems myself and someothers have been having and any
> > > > help or input would be much appricated. The responses would help all
> > of
> > > > us, I think. If anyone has a question to add to this lidt plese do so
> > be
> > > > cause it will help us all understand better and mabye avoid future
> > > > problems.
> > > >
> > > > thanks,
> > > > The Solar Head Project people
> > > >
> > > >
> > > > p.s.
> > > >
> > > > for some pictues and my progress to date, go to
> > > > http://mach5.freeservers.com/beam/head.html
> > > > __________________________________________
> > >
__________________________________________
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7521 Wed, 10 Nov 1999 15:33:42 -0700 [alt-beam] Please submit your site Ian Hi all
I have been seeing allot of questions about tutorials and other information
that already exists! So as going with the "BEAM Online - The Yahoo of BEAM"
I would like everyone to submit sites to me. Either your own or someone
else's. I want only direct links so if you know a site with say a photovore
tutorial or good info and a certain robot give me the direct URL to that
page and not the main page or that site (those go into my links page). Also
so it's easier for me please let me know what category it needs to go in.

To submit I need....
Direct URL
Category

How do I know if I should submit a page? If you think the page would be
useful. Submit it.

Thanks

BTW: Make sure you reply only to me and not the whole list.

--------
There is only one true "SyNeT"
BEAM Online - http://www.beam-online.com

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