12.23 Studios

Lab Notes

(01/20/20)

The 100W demo power plant turned out to be simpler than I imagined, as the booster ended up being the actual last glitch...


Comparing the 2A and 4A boosters...


The 14 AWG wire sorted...


The 4a booster prepped for the circuit the first time...


close-up...


The overhauled circuit board still in mock-up form...


The booster is calibrated to output 16V to the charge controller...


By Sun. evening the overhaul was complete, the circuit board cleared the four-way continuity test...


An intact and a blown 3A fuse...


By the time the 3rd 3A fuse blew, I realized it couldn't handle the power loop...


The local auto store did sell 4A mini fuses, but only online; the only 4A blade fuses they did have were the bigger 'ATO' size, along with an inline holder...


Using the other booster module, I soldered together this backup component...


Calibrating the new booster...


The first iteration of the two boosters...


With the backup booster installed, I ran another continuity check and a shakedown run. Just like before, the circuit ran once or twice, then the 4A fuse blew - three of them too... Since I'm not running a B+ line anymore, the fuse TO the booster should copy the boost-buck converter and go AFTER the booster and complete the circuit overhaul...


After de-soldering and re-soldering, the 4A boost coverter modules are done and ready for shakedown testing tomorrow morning - the 4A and a 3A fuse in the mini holder...


Three more blown fuses...


A before picture for the shakedown test - I had two fuses left...


Half of 3.89A, minus 300mA, is a booster current of 1.645A, more than enough to charge the battery bank...


On Fri. at eBay I found my new doohickey - a couple 30W 2A CC CV boost buck converters for $6 total, not from China but Hong Kong - and yeah, on Sat. I called the Berkeley shop to check, but they only had one size boost buck and it only put out 9V max, but I tried...

Five rapid shots within about 20 seconds of the split current reading for the system...






The current situation is damn good; my demo power plant is kicking, and until the saddle arrives, I have a couple weeks to focus on the other major project this year, getting a campervan and going mobile, that's getting its own overhaul...

(01/11/20)



The 2A max boost converter is starting to bite now - the fan motor now jumps to 2.2A at startup, and since I need spares I decided to bump up to a 4A converter but keep the same 16V output and the same 3A fuse....



I rewired the negative switch and split the common ground busbar and copied the other distribution setup, with the ground wire from the boost-buck converter on the run side, and the charge controller battery negative wire on the charging side....



Now that the boost converter negative wire is unkinked and the solar input light is on, the data sheet from the controller comes in handy...



The rest of the data sheet...



It's hard to see, but the high voltage batteries are being charged as the battery light is slowly going from red to amber, indicating that the controller is sending a full charge to the secondary battery...



The 4A boost converter and spare...


(01/03/20)


On New Year's Eve I fixed what I hoped were the last two circuit design bugs in the system - 1. a set of battery cables made with the 12 gauge wire I was saving for the 600W model, which is a bit overkill but to reduce the resistance as much as possible at the start. 2.) an unbalanced power distribution through the positive switch, caused by the crossover wires.

To fix that I came up with splitting the crossover wires and employing one-port postive busbars for the new power distribution system that isolates the two sides and balances out the positive flow. The A+ and B+ power loop wires are 2.5" long, and the A+ load tap wires are 4" each. To make room. I bobbed the negative switch crossover wires, thinking that was all I had to do there. With the bigger battery cables I thought that was the last bug in the system, so I turned back to the little V-A meters, to see if I could still avoid the current clamp...



The system on Monday still charges slowly on the A-to-B side as the phone charges quickly...



Twenty minutes later, the phone is done, but the charging battery has barely moved...



The mini V-A meters came in days early (with the different wire sets that are common nowadays)



The one-port postive busbars for the power distribution system...



The new system eliminates the crossover wires and isolates the sides through mirrored connections...



The busbars in mock-up placement...



The negative switch crossover wires shortened to make room for the busbar...



The power distribution nodes mounted and glued in place...



The newly evolved system running the fan motor through the A-to-B side. The rate of charge is faster with the larger load...



The fan motor/laptop load is what fried the flimsy clip leads before, so I made battery cables with the 12 gauge wire...



The charging battery has this reading with the system under moderate load...



Turn the load off and half a volt returns...



With the new battery cables, hopefully that's the last bug in the device...



The AC/DC Current Clamp Meter for sale in SoCal...



The circuit design for Electronoobs' DIY DC Current Clamp...



Maybe the Volt-Amp meters will work with the improved circuit design...



By powering the meters separately, the system might tolerate the ammeter shunt and continue charging the batteries normally...



A quick and dirty mount for the 9V batteries...



I plugged in the laptop, got a bit of clicking, disconnected A-to-B and reconnected B-to-A, the laptop brick stopped clicking, but a diode within the common ground fried under a 5 amp surge. This isn't a bug - the crossover cables on the negative side had to be modified as well...



The negative crossovers in a 'combining the negative' layout that resolves the 'splitting the positive' layout at the front end of the circuit...


I finished that part late last night with a pair of 4" wires from the common ground busbar to the separate sides. That's as far as I got, so this weekend I'll see if this long shakeout session bears fruit, or whether I still have to use a current clamp in order to get on with coefficient testing...


(12/28/19)



The volt-amp meter attached to the project board...



The little volt meters...


The clip leads updated with 18 gauge wire...



I hoped that the meter would be better than a sole ammeter...



The charging battery only went up by 100mV; the volt-amp meter is too much for the system...



The system with no current meter does charge the 'B' side, but the AC clamp wouldn't even read AC current from the laptop power cord...



A DIY DC current meter, made by Electronoobs AKA Vladimir Espinoza, a mechanical engineer from El Salvador with a cool DIY Electronics website and YouTube channel...