Pignose 7-200 Hog 20 - charging/powering

[jondoe]

It's already back with it's owner so I may not get the opportunity to do that, it was also a welded shut design so no option to open it up that wasn't destructive. It has a charge status light for added bonus

For reference the current type of charger supplied looks like this, nothing like the one on their website;

[Enzo]

Adaptors rated 12v will always read high until the current drawn from it is the rated current. In other words, if you darg 2A out of it, it ought to drop to around 12v. They are not regulated.

[J M Fahey]

Oh, it reads: Input 100:240V so it´s definitely neither the classic type I thought nor mine, but an SMPS to begin with.

So probably more or less "intelligent" and perhaps related to Cellphone battery chargers.

I´d expect it to provide somewhat constant current charging with some automatic cutoff once it detects battery is full or voltage surpasses 14 or 15V.

[jondoe]

Oh, it reads: Input 100:240V so it´s definitely neither the classic type I thought nor mine, but an SMPS to begin with.

So probably more or less "intelligent" and perhaps related to Cellphone battery chargers.

I´d expect it to provide somewhat constant current charging with some automatic cutoff once it detects battery is full or voltage surpasses 14 or 15V.

If I ever get my hands on one that is my own rest assured I'll bust it open for science

[Mick Bailey]

I did cut one of the older linear charger/supplies open. It's a transformer, bridge rectifier and capacitor. It supplies way too much current and not enough voltage.

[jondoe]

I just got my hands on a "faulty" Pignose Hog 30, the batteries were not holding a charge being the fault. On inspection they were using an after market 12volt adaptor which was of course not charging the batteries, I guess this must be common when owners lose/break their original chargers.

After a bit of research I've found a suitable alternative to the Pignose official charger, it's for a children's 12v scooter which has the same type of batteries

[J M Fahey]

I fear it being for a motor type absolutely non Audio use that type charger will be ugly noisy, scooters don´t care what they are fed as long as the battery is charged, they might very well supply *unfiltered* rectified AC

as in fact tons of battery chargers do, same as done for ages for car battery chargers (hint hint both for "motor" battery use).

They may also offer little current limiting , no voltage control, no auto charge control, you just unplug them after "X" hours, period, or watch the little meter or Red overcharge Led to do so.

I would use anything but a motor battery type charger.

And amp will probably hum a lot while charging so you can not simultaneously play and keep amp charging which is sometimes needed.

I really suggest using a safe and clean charger, such as the cheap (about $2 in parts) add-on regulator plus any >18V supply, be it a laptop brick or self made one.

[jondoe]

The particular scooter/ebike charger I found isn't the cheapest kind I've seen available, it's an automatic kind in much the same way as the Pignose charger has a red LED for charging, green LED for charged. It also states it has a variable current output of 0.1 to 1.0A. As for the noise levels, the official one is noisy as hell, you wouldn't want to play while charging at the same time, unless you like a backing track of static/hum

It's fairly inexpensive and I don't have a laptop charger spare, so it's worth a gamble. As I'm paying for it I'll also take it a part to see what's inside

[jondoe]

So I finally received the super cheap generic charger in the post, I don't have the Hog to test it on right now, but I did wire it up to a small battery I had from a UPS, to check that it functions. It puts out 15v with no load and 13.7 on charge at 0.7A, with 20mV of AC. The battery I had to hand was already fairly full so the charged light came on pretty quick, I intend to run it down and charge it up again, just to see it does what it needs to do.

Bonus picture of guts, very cheap and cheerful!

[J M Fahey]

Cool.
A perpendicular picture, with PCB filling screen end to end and all parts visible would be fine.
Same but from copper side would be the icing on the cake.

[jondoe]

This is about as good as it gets with my camera phone and a bench lamp

[J M Fahey]

Thanks

I expected a driver IC on the other side of the Transformer and very intrigued by finding none. WTF?

[MasterSpoon]

Hello, new to the forum, figure might be best to ask for help here rather than start a new topic.
I recently picked up a used Pignose Hog 30, seller advised that it came with the AC adapter and the batteries were good.
Would only turn on if plugged into power, tried charging it with included adapter and that did nothing. Pulled the batteries, they were under 3v each, plugged them into a Lead Acid Battery charger. Managed to get them charged back up a bit but they are essentially no good and need replacing. Checked the included AC adapter and it is a generic power pack and not a battery charger so likely why it wouldn't charge the batteries...

This lands me where I am at the moment, I could replace the batteries in the unit but I still don't have the correct charger so I figure if I'm going to be looking at batteries and charger there is no need to stay with SLA batteries. Like probably everyone these days I have 18v power tool Li-Ion battery packs hanging around, so why not use them?

The battery and AC adapter are both just connected to the 12v input on the PCB, it doesn't select which power to use, nor does it care what is supplying the power. There is one power input on the PCB and if there is power there it is happy.

I have already done some basic testing to make sure what I am wanting to do should work. I have confirmed
- Amp runs fine with battery completely disconnected and running off AC power pack only
- Amp runs fine with DC-DC Buck converter (LM2596 module) being fed 18v from power tool battery and bucked down to 12.5v (this has about 15mA draw when amp is off so would flatten the battery over time if left connected)

My plan, and this is where I need help to pull it all together fully from those electrically smarter than I, I would like to set it up so it can run off my 18v power tool batteries & AC power pack but with included smarts to avoid accidental damage of anything. My thought so far is using something like a YX850 automatic battery backup switching module to avoid the buck converter output and the AC power pack output being connected together. Using the buck converter to drop the 18+ volt battery output so as to not damage the amp (unless it is safe to run it at higher voltages?). I would like to add some form of low voltage cutoff for the battery so I don't accident drain them too far and damage my batteries, not sure what is a good option here?. Bonus would be to automatically disconnect the buck converter when not in use to save me having to remove the battery all the time.

Any guidance on a good (preferably cheap and easy) battery min voltage cutoff and way to automatically disconnect the buck converter when not in use would be very welcome.

Pictures of both sides of PCB and amplifier chip in case of assistance.

[luigiman]

I have a similar question to MasterSpoon here. I also have a Hog 30 with dead batteries. I would also like to upgrade to li-ion batteries of some kind. But I notice that the TDA7240A amp chip and the NJM4558 op amp are rated for up to 18V. So would it be bad to just supply the board with 18V? Would make the amp a bit louder...

[nmjake]

I'm with you luigiman! I've got a Hog 20 with dead batteries; replacing with lead-acid batteries in 2022 seems odd. I'd love to change them out for Li batteries. Has anyone done that, or tried to do so? Thanks!