This is in reference to the following link:
http://www.intermotive.net/odi1.htm
Someone found the price of this was $190, to which I posted:
Like every other Gen1-er I just pop it off every time I pull it into
gear. But, I seem to recall that the circuit schematic shows the OD
button circuit as "active high" logic. It's near +12v until you
close the switch and pull it to ground (logic 0). This toggles
the circuit off, where it remains even after the button is released
and the voltage at the input goes back up. Press the OD button again
(grounding to logic 0) and it toggles OD back on.
In logic circuits, if you want to make sure they turn on/power up in
a certain mode you use a power-on reset circuit. This is nothing
more than a resistor and a capacitor (in series) connected between
B+ and ground with the logic circuit connected by a second resistor
(for current limiting) to the midpoint of the RC.
http://sigcon.com/Pubs/edn/por.htm
At power-up the cap is at 0 volts and looks like a logic 0, this
would pull the OD input low just like the button. However in a few
seconds the cap charges throught the resistor from B+ and becomes
logic 1, but the OD doesn't care since it responds only to logic 0.
The OD button is free to toggle it back low any time you want to
turn it back on.
A little experimentation is required to get the component values
right.
It would be really annoying to pay almost $200 for a little plastic
box, three parts and a bit of wire.
THERE - I've sat on this bit of info for 7-8 years, now it's out,
someone prove me right or wrong!
Mel C.
93 garnet/grey X2
Garage Queen w/ Ugly Twin
Note: The editor of the article badmouths the circuit, but as they
say, "This ain't rocket science." and it works 90% of the time.
http://www.intermotive.net/odi1.htm
Someone found the price of this was $190, to which I posted:
Like every other Gen1-er I just pop it off every time I pull it into
gear. But, I seem to recall that the circuit schematic shows the OD
button circuit as "active high" logic. It's near +12v until you
close the switch and pull it to ground (logic 0). This toggles
the circuit off, where it remains even after the button is released
and the voltage at the input goes back up. Press the OD button again
(grounding to logic 0) and it toggles OD back on.
In logic circuits, if you want to make sure they turn on/power up in
a certain mode you use a power-on reset circuit. This is nothing
more than a resistor and a capacitor (in series) connected between
B+ and ground with the logic circuit connected by a second resistor
(for current limiting) to the midpoint of the RC.
http://sigcon.com/Pubs/edn/por.htm
At power-up the cap is at 0 volts and looks like a logic 0, this
would pull the OD input low just like the button. However in a few
seconds the cap charges throught the resistor from B+ and becomes
logic 1, but the OD doesn't care since it responds only to logic 0.
The OD button is free to toggle it back low any time you want to
turn it back on.
A little experimentation is required to get the component values
right.
It would be really annoying to pay almost $200 for a little plastic
box, three parts and a bit of wire.
THERE - I've sat on this bit of info for 7-8 years, now it's out,
someone prove me right or wrong!
Mel C.
93 garnet/grey X2
Garage Queen w/ Ugly Twin
Note: The editor of the article badmouths the circuit, but as they
say, "This ain't rocket science." and it works 90% of the time.
