Powering up a Car Antenna a "different" way

[Welchs101]

Hi, I have a friend who has this car antenna and he uses it to open / close his chicken coop. Anway, the operation of the antenna which ihave included pictures of below works in the following way:
Using a 9V batter to make antenna "function":
1)Attach black wire to negative terminal of 9v battery
2)Attach red wire to positive terminal of 9v battery
3)take green wire and touch positive terminal of battery. When you touch green to positive the antenna "goes up". If i remove the green wire from positive lead antenna comes down.

My friend wants this operation to change. Instead of going up he wants the antenna to come down when i touch green to positive terminal.

[R_J]

Re: Powering up a Car Antenna a "different" way

You can try reversing the wires on the motor, that might work, it is just a simple relay that drives the motor but there will also be upper and lower limit switches and they may have diodes across them which might need to be reversed also.
The limit switches are needed to stop the motor from running once the antenna has reached the inner or outer limit.

[Welchs101]

Re: Powering up a Car Antenna a "different" way

Question1: What is the "thing" on the printed circuit board that is a rectangular greyish like box?

Question2: Why is it that when the green wire is "removed" from the + voltage of the battery that the antenna has "power" to move?

[stj]

Re: Powering up a Car Antenna a "different" way

box is a relay, a magnetic switch.

the relay reverses the motor wiring to change direction, and the motor stops at the ends because of limit switches.

[R_J]

Re: Powering up a Car Antenna a "different" way

There are likely diodes across the limit switches so when a limt is reached the switch opens the circuit to the motor, so to enable the motor to operate when the voltage is reveresed, a diode is placed across the limit switch, this allows the reverse voltage to run the motor untill the switch closes. There will be two limit switches so you would need to reverese the diode dirction on both switches.

You can't just reverese the motor connections because of the diodes across the limit switches.

[Welchs101]

Re: Powering up a Car Antenna a "different" way

where do you think the diodes might be? all i see is this thing (see picture)

[R_J]

Re: Powering up a Car Antenna a "different" way

They would be across the switch contacts. if they are not used it may not be as simple as reversing the motor wires.

[Welchs101]

Re: Powering up a Car Antenna a "different" way

i cant find any diodes any where. I did try flipping the wires to the motor but this did not seem to work.

also, i noticed that the "gold" circular thingy in my previous post turns every so often when the antenna is going "out/up". Once fully up it stops turning. When i remove power from the green wire gold thingy turns more and then finally stops. I some how thing its this gold thingy that is "switching" the voltage but i am not sure how.

anyone know how this thing is supposed to work?

[R_J]

Re: Powering up a Car Antenna a "different" way

The gold thing is the switch, it is a rotary switch. Because of the gear setup, simply reversing the motor won't work because it will try and run against the mechanical end of the travel.

[petehall347]

Re: Powering up a Car Antenna a "different" way

post a pic of relay wiring .

[sam_sam_sam]

Re: Powering up a Car Antenna a "different" way

Try this unsolder the motor leads and see if the motor will run in both directions BUT do NOT let it run very long because you might damage the gearbox if it was not meant to run backwards

[R_J]

Re: Powering up a Car Antenna a "different" way

It would seem the only reason for switching the direction would be because when the green wire has power applied, the antenna is extended and the relay is energized and drawing current.
You might be able to reverse the power leads going to the board, that should cause the antenna to extend when power is applied and stop at the extended limit, Then to retract the antenna all you need to do is connect the green wire to the negative of the battery which will energize the relay.

[Retro-Hipster]

Re: Powering up a Car Antenna a "different" way

Hmmm..... From what I could trace visually Sir, if you reversed the red and black wires, you would then need to touch the green wire to the NEGATIVE of the battery. Give that a shot. You may want to check the relay model and just verify that the datasheet doesn't show any diodes in the package first though. You'd normally expect a diode across a relay, so it's wierd that there don't appear to be any on that board. It might be internal on that relay...

[redwire]

Re: Powering up a Car Antenna a "different" way

The limit switch is what latches power and keeps the motor running until it reaches an endstop. Not SPDT but it shorts the two ends until an endpoint. No need for diodes then.
Schematic might look like this, I assume a PTC is stashed in there too.

[Welchs101]

Re: Powering up a Car Antenna a "different" way

switched red and black keeping black wire on negative terminal and red on positive terminal. touching green wire to negative terminal does make motor turn to "lower" the antenna. However, when i remove green wire motor does not turn to "raise" antenna.

Also, redwire can you explain the picutre you sent. Not sure i understand it.

[sam_sam_sam]

Re: Powering up a Car Antenna a "different" way

The limit switch is what latches power and keeps the motor running until it reaches an endstop. Not SPDT but it shorts the two ends until an endpoint. No need for diodes then.
Schematic might look like this, I assume a PTC is stashed in there too.

switched red and black keeping black wire on negative terminal and red on positive terminal. touching green wire to negative terminal does make motor turn to "lower" the antenna. However, when i remove green wire motor does not turn to "raise" antenna.

Also, redwire can you explain the picutre you sent. Not sure i understand it.

If your drawing is correct then that would explain what you are seeking

you would have to run the motor to end of travel before you can get it to travel in other direction to change the status of the limit switch

[redwire]

Re: Powering up a Car Antenna a "different" way

With nothing to the relay coil (green), see the diagram- it shows power can flow to the motor until the antenna-down limit-switch upper contact opens and disconnects the motor power.

With the limit-switch now at one end (its upper contact open and lower one closed), the only way the motor can get power is if the relay is pulled in (with power on green wire). This gives reverse polarity power to the motor, so the antenna can go up.

If power to the relay (green wire) is removed too soon, i.e. the antenna only made it half way up, the motor reverses and continues to move the antenna down.

So the green wire seems to be an "antenna up" wire that needs power for the whole time the motor is going up. The limit-switch always disconnects power to the motor at either end.

You want to flip this "My friend wants this operation to change. Instead of going up he wants the antenna to come down when i touch green to positive terminal. "
You'd have to rewire the relay contacts so defaults to moving the antenna up, not down. I'll have to draw it later but I think 4-wires to move - swapping the NC and NO connections?

[Welchs101]

Re: Powering up a Car Antenna a "different" way

hi redwire, i dont totally understand but i need to read you explanation a few more times with the picture in front of me.......one qustion i do have is what for wires need to move and where move them to? i can take another picture of the relay and motor if this helps.

[Welchs101]

Re: Powering up a Car Antenna a "different" way

i am enclosing the front and back views of the antenna showing how the wires are connected.

[Welchs101]

Re: Powering up a Car Antenna a "different" way

Really sorry but i guess i just dont understand the drawing. For example, com1 and com2. They are switches and they appear to be somehow involved/connected with the blue dotted line........what does this mean?

What are N/C and N/O?