Alt-BEAM Archive

Message #11876



To: beam@sgiblab.sgi.com
From: "Corey Centen" biobotics@hotmail.com
Date: Wed, 15 Mar 2000 09:36:52 EST
Subject: [alt-beam] FRED Componenet alternative


Sorry - one other question,

Is it possible to make some componenet changes in the FRED design. Have a
4700uf cap and 2.2k resistors instead of 4.7uf cap and 3.3 resistors?
______________________________________________________



11877 Wed, 15 Mar 2000 09:33:43 EST [alt-beam] FRED solar panels beam@sgiblab.sgi.com "Corey Centen" Ben..or whoever can answer,

Will calculator solar cells work for the FRED design? If I wire two together
to increase the voltage, or even one might be enough. What do you think?
______________________________________________________



11878 Wed, 15 Mar 2000 07:07:33 -0800 [alt-beam] Re: H-Bridge "'beam@sgiblab.sgi.com'" Wilf Rigter A word of caution: the latching h-bridge circuits are special designs
serving as a memory for the last input state.

Ben's simple inverting buffer is inherently safe and recommended for many
general applications. Note that most h-bridges including Ben's cannot be
connected directly to the output of Ian's reverser (Mattmux) : the 47K
output resistance in the reverser non-inverting mode limits available drive
current. Add an extra 240 inverter between with each reverser output and the
h-bridge inputs to fix the problem

wilf

> -----Original Message-----
> From: Andrew Hooper [SMTP:andrew@best.net.nz]
> Sent: Tuesday, March 14, 2000 5:39 PM
> To: beam@sgiblab.sgi.com
> Subject: H-Bridge
>
> 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



11879 Wed, 15 Mar 2000 09:26:57 -0600 [alt-beam] Radio Shack Voice Chip and Sound Recording.. "beam@sgiblab.sgi.com" Kelly Petriew I've come across this numerous times in my wanderings.
If you want a bigger selection of voice chips than just Radio Shack,
check out page 136 of the Digikey catalog.

http://www.digikey.com/EC/V3/136.pdf

The above page actually has a circuit diagram to make a simple recording
device.

I believe Radio Shack Voice recorder is made by ISD and I've heard
rumblings that it doesn't really satisfy for the price (they are
charging WAAY too much for it). Make sure you have a decent imput
sample rate for clarity (with reduced message length). Here is a link
to ISD's website with samples of different input frequencies:

http://www.isd.com/products/chipcorder/

Packages are 28-DIP and 28-SOIC

The 1100, 1200, 1400, 1500, and 2500 series would suit BEAM needs as
they are 5 volt and operated by simple pushbutton. Imagine your robot
walking around spouting off for up to 2 minutes about its living
conditions in the RJP using the ISD2512-ND chip!

PS: the 2500 series are cascadable for longer durations and adressable
for multiple messages..

I know we're getting borderline for BEAM app, but the thought of a
Walker spouting off randomly is amusing.

--
Kelly Petriew

Systems Support Analyst
The StarPhoenix
204 5th Avenue North
Saskatoon, Saskatchewan
Canada
S7K 2P1

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