The Continued Saga of the Search for Qbert's Knocker (Hardware)

[Curtishart001]

Hitting brick walls is no fun. Software seems to be working. MAMEHooker is capturing. I even had PacDrive hooked to an LED light for testing and it flashes when Knock=1.

Now wiring the hardware, I'm stuck (again)

Hardware

• Q*BERT KNOCKER ASSEMBLY WITH 12V COIL https://www.arcadeshop.com/i/1125/q-bert-knocker-assembly-with-12v-coil.htm
• 5v 1 Channel Relay https://smile.amazon.com/gp/product/B079FJSYGY/ref=ppx_yo_dt_b_search_asin_image?ie=UTF8&th=1
• Ultimarc Pac-Drive https://www.ultimarc.com/output/led-and-output-controllers/pac-drive/
• Fuse 3ag holder w/fuse
• 12v AV Adaptor

Here's my current wiring (yes, I have a fuse in the holder of the real thing ):


Wiring Summary

• RED PacDrive +5 to Relay DC+
• BLACK PacDrive Port1 to Relay DC-
• BLUE Relay COM to Knocker (Sorry, not sure which is + or - on there)
• GREEN AD to Fuse to Knocker
• ORANGE AC to Relay Normally Open (NO)

When I test it, the knocker doesn't engage when needed to. However, I see the LED on the relay flash, indicating it's receiving the instructions.

I've also directly connected the AC Adaptor to the Knocker without the other electronics and it engages when I touch the leads.

Lastly, I changed the blue wire from NO to NC and it's repeatedly engaging because the circuit is closed.

Any ideas? I'm so close to this it's really frustrating, especially if it is a simple solution I overlooked. 

Oh, and my qbert.ini looks like this FWIW:

Code: [Select]

Qbert.ini
[General]
MameStart=uls 1 1 0
MameStop=uls 1 1 0
StateChange=
OnRotate=
OnPause=
[KeyStates]
RefreshTime=

[Output]
knocker0=uls 1 1 1,wat 50,uls 1 1 0
Thanks all!

[PL1]

Wiring Summary

• RED PacDrive +5 to Relay DC+
• BLACK PacDrive Port1 to Relay DC-
• BLUE Relay COM to Knocker (Sorry, not sure which is + or - on there)
• GREEN AD to Fuse to Knocker
• ORANGE AC to Relay Normally Open (NO)

From the relay board product description:

Module interface
DC +: positive power supply (voltage by relay requirements, 5V.9V.12V and 24V selection)
DC-: negative one
IN: can be high or low level control relay

You've got the relay control on the wrong terminal ("DC-" instead of "IN") and no constant ground for the relay on "DC-".

1. Move the BLACK PacDrive Port1 wire from Relay "DC-" to "IN".

2. Add a ground wire from USB ground (or molex or the computer PSU frame -- they're all tied together) to Relay "DC-".
NOTE: There is no screw terminal connection for this ground wire on the PacDrive.
- You might be able to get away with a jumper from Relay "DC-" to "IN" so PacDrive Port1 provides ground for both the relay and switch control.   

3. Confirm that the jumper is set to "L" instead of "H" so the relay triggers when ground is applied from PacDrive Port1.


Scott

[Curtishart001]

That did it! Many, MANY thanks for this.

Question if you don’t mind. I’m using a 12v knocker with a 12v power supply. But the ‘kicker’ seems weak. It doesn’t even have enough power to push the solenoid when the kicker is upright. And when it’s at about. 45 degree angle it still sounds weak, compared to what I remember.

Should I change to a 30v knocker w/ps or can I just use a higher voltage ps with the 12v knocker to give more “knock”?

[pbj]

Crank up your volts,  it doesn’t fire enough to hurt anything.

[PL1]

That did it! Many, MANY thanks for this.

Glad to assist.   

I’m using a 12v knocker with a 12v power supply. But the ‘kicker’ seems weak. It doesn’t even have enough power to push the solenoid when the kicker is upright. And when it’s at about. 45 degree angle it still sounds weak, compared to what I remember.

Should I change to a 30v knocker w/ps or can I just use a higher voltage ps with the 12v knocker to give more “knock”?

1. You did mount it upright with the screws on the top side and the rubber bumper on the bottom side so gravity pulls the plunger down when the solenoid isn't activated, right?



2. Did you connect the leads on the coil in the right polarity?
- There's a reverse-biased snubber diode on the coil.
- Connect the leads so the tab connected to the band end of the diode (cathode, right tab in pic) is on the green wire/fuse/12v and the tab connected to the other end of the diode (anode, left tab in pic) is on the blue wire/ground.



3. If you got the physical orientation and snubber diode polarity right, but it still doesn't work, the 12v power supply you used probably doesn't supply enough current for the coil when it fires.

This post says the A-5194 coil draws about 2.7A, so a power supply rated for 12v@3.5A should be good.

You might be able to use a power supply rated for less current draw with an electrolytic capacitor, but I'm not sure how large a capacitor you'd need for this application.   


Scott

[Curtishart001]

Sorry, I meant to reply to you about this sooner. I think I did something wrong originally because now with the 12V PS it's working great. Again, thank you so much for the help on this. Super excited to get this thing integrated now.