46 replies to this topic

[Tesla]

Well, the Shelly-1 Relay Switch works fine to control the 12-volt power-supply to the 3-Relay Speaker Protection Board via WiFi. It now turns On-and-Off at appropriate times. This prevents the ZK-TB21 from being able to pop/thump the speakers at its power-down time.

 

Bench-testing is complete, and the computer is already controlling it at Windows ShutDown and Startup. I just need to install the whole-solution inside my pinball-cabinet and hook-up its speakers and amp instead of the test-ones.

Edited by Tesla, 01 January 2026 - 04:21 PM.

[Tesla]

@RickH,

 

So, if this Buck-Converter with LED says "Input Current: Up to 3-amps max.". does that mean I can draw up to 3-amps at 12-DC for up to three of these 3-ch Speaker Protection Modules?

 

They say 300watts, but since it is not an Amp, I think that is just "handling power" of the speaker inputs. I don't see where it says how much power they need to run, but I was thinking less than 0.5 amps each. What say you? Is it close enough that you think I should try hooking-up the DMM and try to measure the amp-draw of one? 

[rickh]

@RickH,

 

So, if this Buck-Converter with LED says "Input Current: Up to 3-amps max.". does that mean I can draw up to 3-amps at 12-DC for up to three of these 3-ch Speaker Protection Modules?

 

They say 300watts, but since it is not an Amp, I think that is just "handling power" of the speaker inputs. I don't see where it says how much power they need to run, but I was thinking less than 0.5 amps each. What say you? Is it close enough that you think I should try hooking-up the DMM and try to measure the amp-draw of one? 

I would not trust these modules past 1.5 Amps for continuous use. However, you can run it at the max current provided that the module does not overheat.  I think you are using these buck converters for running that speaker relay controller board.  If so, the buck converter should be adequate for driving that board.  BTW- relays are rated by current and voltage, but not wattage.  For the sake of brevity,  I will not go down a rabbit hole on this.

 

Happy New Year,

 

Rick

[Tesla]

 

@RickH,

 

So, if this Buck-Converter with LED says "Input Current: Up to 3-amps max.". does that mean I can draw up to 3-amps at 12-DC for up to three of these 3-ch Speaker Protection Modules?

 

They say 300watts, but since it is not an Amp, I think that is just "handling power" of the speaker inputs. I don't see where it says how much power they need to run, but I was thinking less than 0.5 amps each. What say you? Is it close enough that you think I should try hooking-up the DMM and try to measure the amp-draw of one? 

 

1. I think you are using these buck converters for running that speaker relay controller board. 

 

2. If so, the buck converter should be adequate for driving that board. 

 

3. I would not trust these modules past 1.5 Amps for continuous use. However, you can run it at the max current provided that the module does not overheat. 

 

4. BTW- relays are rated by current and voltage, but not wattage.

 

5. For the sake of brevity,  I will not go down a rabbit hole on this.

 

 

 

1. Correct. Since it seems to be working, I went ahead and ordered another (for the next set of Amps and speakers and/or transducers/exciters).

 

2. Yes, bench-testing revealed that. But I was thinking of installing it all inside one larger project box. I was just wondering if it's an accepted practice to run two or more from one Buck-Converter.

 

3. I think you are saying to not try pushing them very hard (like stay on the safe side around 50% utilization) and watch the temps. 

 

4. Understood

 

5. That is fine. I'm really just looking for directional guidance (and only if you have time). I'm happy to do any "rabbit-hole digging" myself. For the sake of designing a viable solution, I'm just trying to design and build something good. Not just hook-up some stuff and see if it works without over-heating or blowing-up when pushed.

 

I'm not building an automobile, but I suppose there is something to be said for Redundancy ... even on a few-hundred dollar sub-system as part of a few-thousand-dollar machine.

Edited by Tesla, 01 January 2026 - 05:21 PM.

[rickh]

Tesla,

 

2.  I think it's okay to run two of these relay boards from the same buck converter

3.  Yes, this is on a conservative estimate, as I mentioned that some of these regulators might be counterfeits, they work, but not efficiently.

5.  I started going into the nitty gritty details of the relay, and that is why I pulled back.  Most people reading this thread are not electronic enthusiast, so I keep it light and easy to read.

 

Regards,

 

Rick 

[Tesla]

Tesla,

 

2.  I think it's okay to run two of these relay boards from the same buck converter

3.  Yes, this is on a conservative estimate, as I mentioned that some of these regulators might be counterfeits, they work, but not efficiently.

5.  I started going into the nitty gritty details of the relay, and that is why I pulled back.  Most people reading this thread are not electronic enthusiast, so I keep it light and easy to read.

 

Regards,

 

Rick 

 

2. Agreed. Looks like 2 or even 3 are no problem.

 

Fluke-179 DMM says about power-draw on the 3-Relay_Speaker-Protection-Board:

 

Initial power-up and for 5-seconds = 4mA

After Relays kick-in = 67mA

As expected, volume level makes no difference. After 10 minutes, (and cranked-up loud) just hovers around = 67mA

 

All the parts on the Buck-Converter were still just room-temp (barely even lukewarm).

 

3. I remember. That spurred the curiosity, post, and investigation.

 

5. I'm just building (and enhancing) my one pinball-cabinet. Sure, to play pinball but I'm enjoying getting back into electronics (lots of new modules and tech to play-with now-days). I've had the Fluke-179 DMM for a year or so now, but this was the first time I actually used it to check amp-draw (or even a reason to). Very cool to actually know and removes a lot of the questions and mysteries.

 

Thanks for the help. OK, so now bench-testing is REALLY finished. All these modules are so tiny. Time to design a box for it (at least THAT can be mounted somewhere inside). I think I will work toward something easily removeable or relocatable (if needed later).

Edited by Tesla, 02 January 2026 - 12:07 AM.

[Tesla]

OK, I built it and it works fine:

 

https://www.vpforums...=52387&p=551897