RE: SV: SSRs, relays, speed controls

["flier" <FLIER-at-sbcglobal.net>]

Right on Steve!


--- Original Message ---
From: "Steve Tyng" <stevet-at-stcharlesmd.com>
To: "tanks-at-rctankcombat.com" <tanks-at-rctankcombat.com>
Subject: RE: SV: SSRs, relays, speed controls

>Joe,
>
>I think you need to bite the bullet and just build a 
full mosfet based dual h-bridge controller.  Forget 
about these reversing relays and over priced SSR's.  
All you need is a bunch of n-channel mosfets (which I 
have) and a quad mosfet driver like the Maxim621 
(http://pdfserv.maxim-ic.com/en/ds/MAX620-MAX621.pdf).
>
>Steve
>
>
>
>> -----Original Message-----
>> From: tanks-at-rctankcombat.com 
[mailto:tanks-at-rctankcombat.com]
>> Sent: Thursday, March 04, 2004 11:19 AM
>> To: tanks-at-rctankcombat.com
>> Cc: stevet-at-stcharlesmd.com
>> Subject: Re: SV: SSRs, relays, speed controls
>>
>>
>> Woops, my mistake.  Takes 8 SSRs since they're spst
>> instead of spdt...
>>
>> --- Original Message ---
>> From: "flier" <FLIER-at-sbcglobal.net>
>> To: <tanks-at-rctankcombat.com>, 
<tanks-at-rctankcombat.com>
>> Subject: Re: SV: SSRs, relays, speed controls
>>
>> >Yep, Bob Blick's code runs at ~20mhz and generates
>> >the PWM outputs inline instead of using the PWM
>> >modules in the PIC.  That setup requires 4 SSRs.
>> >That would still be over $200 wholesale to 
implement
>> >when dealing with high currents.  I'm sure it 
works
>> >good though.
>> >
>> >Someone just needs to find us a source of free 
high-
>> >current solid state relays...
>> >
>> >
>> >
>> >
>> >--- Original Message ---
>> >From: "flier" <FLIER-at-sbcglobal.net>
>> >To: <tanks-at-rctankcombat.com>,
>> <tanks-at-rctankcombat.com>
>> >Subject: Re: SV: SSRs, relays, speed controls
>> >
>> >>Hi Bjorn,
>> >>
>> >>I ran across this the other day.  The interesting
>> >>thing is I don't think Bob's code even uses the 
PWM
>> >>modules of the '876.  I think it's done with 
inline
>> >>code and timed loops but I haven't had a chance 
to
>> >>look it over good.
>> >>
>> >>Thanks,
>> >>
>> >>Ted
>> >>
>> >>
>> >>--- Original Message ---
>> >>From: =?iso-8859-1?Q?Bj=F6rn_Wallentinus?=
>> >><bjorn.wallentinus-at-abc.se>
>> >>To: <tanks-at-rctankcombat.com>
>> >>Subject: SV: SSRs, relays, speed controls
>> >>
>> >>>Don't know if this will help you but there is 
code
>> >>for the 876 on this pa=
>> >>>ge
>> 
>>>http://www.bobblick.com/techref/projects/sv2hb/sv2h
>> b
>>
>>
>>
>>
>>
>>
>