OK, I've double-checked Rev2; found one minor error that only involves reversing the labels (actually, the names) on MOT+ and MOT-.

The Rev2 board is unchanged.

Perhaps I should write up some assembly instructions?

 

Tank Commander Control Board Rev2 Assembly Procedure

1) Orient the board so that the vias for S2, 7.2v and GND are at the top, traces down.

2) Insert D1 and D4 in the 3rd row of vias down; the bands (cathode end) must be towards each other.

3) Insert D3 in the 2nd column of vias from the left; band (cathode) towards you.

4) Insert D2 in the bottom row of vias, using the 2nd and 3rd vias; band (cathode) towards the left.

5) Verify polarity of all diodes using board image.

6) Solder and clip leads of all diodes.

7) Insert R1 in 2nd row of vias. At this point, the board should look as in this image:

8) Insert Q1 in bottom row of vias, flat face towards top of board.

9) Solder and clip leads of R1, Q1.

10) Install and solder RLY1.

 

If anyone is curious about how I produced the image above, I used POV-Ray with the Eagle .ulp add-in.

Link to free download page: http://www.povray.org/resources/links/3D_Programs/Conversion_Utilities/

 

Wow Sarge That image is amazing! The instructions do indeed help. You're a good man Sarge!

Don

 

Ouch - you just bought ONE of those relays?

Well, I very seriously doubt you did any damage to it; the contacts are rated for 30A. I'd bet money that you either used a shorted diode, you inserted one of the diodes backwards, or there is a short on the board that caused the switch to get fried.

 

Oh no I have two, just hoping I could save the other for another Tanker. Let me check my wiring and board again. I'm sure I shorted something out.

Don

 

OK, here's the 3-d pic for the crappy Rev1 board:

Note that the resistor location is different.

I didn't bother to re-verify the schematic or the board; that would imply that I actually liked Rev1. I do not, and I'm sorry that I posted it.

 

Hey Sarge,

Sorry for the delay. The hospital stay was a bit longer than anyone thought. Now I have a curcuit running my ticker. But anyway. I have rev 2 built. It does go around and around but it is as if the reed switches hanve no effect on the relay. I used the ohm meter and sure enough when the magnet passes the switch they indeed close, but the motor still rotates.

Any ideas?

Thanks

Don

 

Gosh, I was wondering what happened to you - had no idea you were going in the hospital. Glad you're OK though.

OK, so neither reed switch has an effect on the relay?
The RX-18 unit does start it going though?

 

Oh yes sir it does indeed and as long as I keep the wire on it continues to run, soon as I pull the RX-18 it stops

 

Seems like your RX-18 is keeping the output held high forever. It was supposed to just output a momentary high when you wanted the TC to begin his turn?

 

Arrgh - found the problem; the anodes of D3 and D4 need to be swapped.

It will be an easy fix, though. Give me a few so I can mark up an image.

 

Thanks Brother!

Don

 

Sorry about that.

It's going to take a bit more than the attached, I'm afraid...

See the next post; you can snip D3 and D4 off the top, and solder new ones on the bottom of the board.

You're going to need to cut a trace and run a jumper, too.

 

Got it, Okay let me try and see what I got.

You're the best! Thanks

Don

 

You're going to have to cut a trace, and solder a jumper. Bottom view:

Fortunately, the traces are right next to each other; and nothing else is in the way. You could use a lead clipping from one of the diodes to make the jumper.

 

Hey Sarge,

That turned out to be a nightmare. Some of the traces were coming up and I had to repair some. Okay got it back together and here is what we have. Switch 2 still does nothing. Switch 3 will stop the motor. But no reversing The RX-18 is now supplying only a pulse to get it going. We are almost there!

 

OK Don, I'm looking at it again.

I've been fighting computer problems again - sudden shutdown for no apparent reason.

 

New deveolpment.

I hooked the circuit to the battery andtook off the lead from the RX-18. I also removed Switch 2 and put thosetwo wires together. I then touched the RX-18 lead to the gound and it started.I then touched the Rx-18 lead to the Hot and it reversed. But when I pull thetwo wires from switch 2 apart it stops.

It still goes pretty fast. Would a resistor on the motor lead slow it down?

Thanks

Don

 

Don,
I've figured out where I went wrong. It involves some confusion I had regarding the layout of the pins on the relay, and repeated flipping of parts around in the schematic vs the board design. Afraid some things may be bass-arckwards on the board.

You still have a relay that's not soldered on a board, right?

Can you take a photo of the bottom of the relay, so that I can verify the library pin layout vs the actual component?

Yes, a resistor can be used to slow the motor speed down.
The motor has an 18mA current draw at 12v with no load. That's roughly 670 Ohms. (wrong way to figure it, but it'll probably work for this purpose.)

I'm thinking around a 220 Ohm 1/4W resistor in series with the motor for starters. See how that works for you.

In the meantime, it would help a good deal if you could post an image of the bottom of the relay.

Also, I need you to verify that there is continuity (<1 Ohm) between pins 1, 5, and 8, and that it is open between pins 4 and 1, and pins 4 and 8.

Since modifying the board to this point was rather a chore, and more mods are in the offing, would you prefer to start with a fresh board that's not hacked up? I've worked up a new layout based on the original schematic; I could easily incorporate the motor current limiting resistor. However, I need you to verify the relay connections are what is shown in the datasheet, and need to ensure that I have my library model correctly defined.

My apologies for being hasty with the earlier boards.