Circuitron BD-1 and Tomar H-858?????

Not sure if I understand you correctly as I am not familiar with the BD-1. It sounds like the Red should be connected to the Occupied connection and the Green to the Clear connection. Next one side of the power source would go to the white common of the LED and the other side to the BD-1. Now it is possible that this will not work if the polarity of the LED is not what the BD-1 requires. Connecting the red and green wires together will not work as this will cause both to come on at the same time.

Stuart Sabatini Palm Coast , FL

Exactly -- you'd think Red ought to go to Occ and Green to Clear, with the one common White wire going to the + source, but then the LED won't light. Reversing the whole deal makes the LED light, but as you say, both Red AND Green light and you get Amber.

Have you tried connecting the white to the minus connection. If this does not work then the LED is of the wrong polarity. The LED is either a common anode or common cathode. If you have the wrong type for the BD-1 then it will not work. To make it work you would have to have the BD-1 control relays and then wire the output of the relays to the LED

Stuart Sabatini Palm Coast, FL

I ws just thinking of experimenting with relays. All I have handy is an Atlas relay which requires momentary power. Is there a relay that can handle the sustained power output of a BD-1?

You must determine the voltage output of the BD-1 and then find a relay to match. You then must make sure the current draw of the relay coil is less than the max that the BD-1 can put out. The relay draws the power so it is not a case of the BD-1 putting out too much, but rather you don't want the relay to draw too much and burn out the BD-1. Relays come in all sizes and a large one could draw too much current from the BD-1. The Atlas is a latching relay that requires momentary power as you noted. This type can not be used in this application. You must use a relay that requires constant power (most relays are of this type). I am turning my computer off now, so I won't be able to help you for a couple of days until I get back. Good Luck

Stuart Sabatini

Measure the DB1 outputs. Does the Occ have a positive voltage when the block is occupied? Does the Clear have a positive voltage when the block is cleared? If so then connect the Occ to Red and Clear to Green and the White to ground. Donald

Thanks, but read again. The LED will not light when configured in such a way. The BD-1 seems to have been designed so that the Occ and Clear are the negative poles.

Just heading out to Radio Shack to see what kind of DC relays they have.

The BD-1 can output no more than 250mA safely, so I'm off the Radio Shack.

What are the actual voltages that the BD1 is putting out when the block is occupied and when it is cleared. Both lines please...

A. The Occ is a plus when not Occupied and negative when Occupied. B. The Occ is a plus when not Occupied and zero when Occupied. C .The Occ is a zero when not Occupied and negative when Occupied. D. The Occ is a zero when not Occupied and plus when Occupied. E. The Occ is a negative when not Occupied and plus when Occupied. F. The Occ is a negative when not Occupied and zero when Occupied. Similar for the Clear line...

If A: Occ goes to Green and CLE goes to Red and Ground goes to White. If B: Same thing. If C: Occ goes to Green and CLE goes to Red and a negative goes to White. If D: Same thing. If E Occ goes to Red and CLE goes to Green and a Ground goes to White. If E Occ goes to Red and CLE goes to Green and a negative goes to White.

The H-858 sounds like it is using a common cathode for the LED....

There are other ways to connect this using just diodes and the just outputs from the BD1:-)

Donald

The BD 1 doesn't output anything through Occ or Clear; they are either negative or zero. The + connects to the LED, the LED connect to Occ or Clear, otherwise the LED won't work.

G. The Occ is a negative when Occupied and a zero when not Occupied.

Thanks, but none of your solutions will work with these Tomar signals.

craig

biff spake thus:

I'm pretty sure most small low-voltage relays draw sustantially less than that.

It may be possible to make this work without a relay. First you must have access to the minus of the power source on the BD-1. No mention of the resistor that is required with a LED has been posted. I assume no resistors already in the wires coming from the signal. Connect the white wire to the minus connection on the BD-1. Connect the red and green wires each to it's own 600 to 1200 ohm resistor. Connect the other side of both resistors together and to the positive side of the power source. At this point both LED's would light as they are simply connected to a power source. Now connect the Occ. connection of the BD-1 to the green wire and the clear connection to the red wire (this is the opposite of what you might expect).

How it works: When the BD-1 indicates occupied the Occ wire should be connected to minus by the BD-1. This would short out the green LED and turn it off. When not occupied the current goes through the resistor and the LED. When occupied the current still goes through the resistor but the BD-1 Occ. wire directs the current to minus by the fact that it is connected across the LED.

Why it might not work: The switch in the BD-1 is a semiconductor not a mechanical relay. It will not be a full short across the LED, some voltage will be present. I don't know if this voltage will be enough to provide some illumination of the LED.

Stuart Sabatini

I wound up adding a Circuitron ER-1 relay and it works fine now.