Changing Photocell's connector Output

Hi,
to make a standard connection -open collector -You need a standard low power NPN transistor(like BC547, BC337), resistor to reduce base current -10 kiloohms, and Zener diode 2.7V or 3.3V to prevent transistor from "rest voltage" on fotocell output, in "low" state slighly higher than 0V.
Everything low power, it`s enough.

Connect serially, from photocell output -resistor,cathode of Zener diode, Zener anode to base of transistor. Ground power(0V) of cell to transistor emitter and standard banana black conector.
Then transistor collector to green banana conector and -voila.

In place of zener diode You can use diode 1n4148(or two serially) but in opposite direction, from cell/resistor-to anode, kathode to transistor base.

Without thiese diodes everything maby would work O.K. but only, if there is not more then 400 milivolts on photocell output in low state.

Wish You only like-this problems!

Jaroslaw
Gro-Timing
Poland

Hi Jaroslaw,

you mean like this:


I do not have a green connector on the Lynx box, but 3 pairs in red and black.
Topmosts is for power output, the to others are cell A and cell B
I asume, that all the black connectors are connected within the box.

So I connect the transistors collector to the red connector of either cell A or cell B...

I will try that...

Thanks

Dirk

Hi Dirk,
the schematic is O.K. and according to Lynx documentation (I got no Lynx) Yours connections will work, as other standard photocell.

Interesting, that they use in Lynx-Connnction Box the same color for different functions.

Jaroslaw Grondal
Poland
www.gro-timing.com

Today, I got the chance to try this out - and it worked...

Thanks

dirk