Relay question

[Mike Stein]

Why not just do this the simple, usual way for an application like yours: a 
pair of nice, sealed, heavy duty industrial pushbuttons marked UP and DOWN, 
or even a single button with a nice heavy duty toggle switch similarly 
marked?

Personally, I'd be a little leery pushing that button without knowing which 
way the lift is going to move when I do...

m

----- Original Message ----- 
From: "Jim Brain" <brain at jbrain.com>
To: <General at classiccmp.org>; "Discussion at classiccmp.org:On-Topic and 
Off-Topic Posts" <cctalk at classiccmp.org>
Sent: Friday, November 28, 2014 5:06 PM
Subject: Re: Relay question


> On 11/28/2014 2:23 PM, Chuck Guzis wrote:
>> On 11/27/2014 11:23 PM, Jim Brain wrote:
>>
>> I'm trying to wrap my mind around the problem.  Does this describe it?
>>
>> You want a push-on push-off circuit using only mechanical relays.
>>
>> Am I reading you correctly?
>>
>> --Chuck
>>
>>
> hmm, not exactly....
>
> To translate into electronics, it'd be like:
>
>  * Take a D FF
>  * hook it up in std divide by 2 mode (i.e., !Q = D)
>  * Take Q and attach it to a latch input with active enable line
>  * Take latch enable line and hook to CLK
>
>
> So, on first CLK, the FF goes to 1, and the Latch allows 1 to flow out of 
> the unit
> When CLK goes LOW, output goes to HiZ
> When second CLK arrives, output goes low
> When CLK goes low, HiZ
>
> Output = 1 (hydraulic motor send lift up)
>
> Output = HiZ (hydraulic motor off)
> Output = 0 (hydraulic motor send lift down)
>
>
> Jim
>
> -- 
> Jim Brain
> brain at jbrain.com
> www.jbrain.com
>