12.23 Studios

Lab Notes

(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...

(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...


(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...


(01/20/20)

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...

(02/02/20)

Ok, while it's downtime waiting for the new part, I focused on the mobile lab-studio campervan plan. The reason why hasn't changed - the rent is too damn high and I don't wanna get stuck. And since I do have a vehicle - an old Diamondback hardtail steel MTB, built like a tank - I should actually bug out, put my stuff in storage and go Walkabout...


The MTB when I got it in 2016...


General purpose street/offroad tires. Not putting them on until after I get some riding in...


The rear rack for panniers and a cargo trailer hitch mounted on the end...


The 25W boost buck converters arrived early, so the lab is back up on Monday...

(02/08/20)

Ok, new week in the lab, working on the power plant and the bike...


Calibrating the new boost buck converters. I'm setting the output at 17V over 16V because that is the 'rated terminal voltage of the average 12V solar panel'...


I slowly set the current to 1.5A, looking for any sign of blue smoke...


Calibrating the second converter...


Current set, and a reminder to get another cheap multimeter...


After cleaning and resoldering my iron, I de-soldered and re-soldered the wires to the new converters...


The unit with the regular fuse holder will be installed to the board...


During the Thur. shakedown test, I read 1.5A from the run battery with just the power inverter connected...


With the phone charger connected, the current draw is 1.8A...


The fan motor at the highest setting only pumps the steady current draw up to a max of 3.2A; anything over 1.5A goes to the load taps...


With the laptop plugged in, the heavy 90W load spiked to just over 3A, then settled between 2.5-3A. No more 5-6A surges; the system is locked down and under control...


The bike trailer design, a DIY bamboo copy of the Burley Travoy trailer. While I search for bamboo, I can make a pvc mockup. Source: see YouTube and Instructable 'How to Build a Bicycle & Hiking Trailer with Bamboo - BooTec'...


The first two bamboo poles for the trailer - about 1.5" dia., 4 ft.long. Five poles should do it...


The rear rack is sitting far enough back that I could hang a big grocery store size bag off it and it just might clear the back of my feet. Changing the depth from 15.5" to 14" should fix that too...


I tested it out with a big shopping bag - placing the leading edge a few inches back on the rack looks cleared of the foot path...


My old tire pressure gauge was busted, but the bike shop only had digital models, luckily the local REI had an analog gauge. This is in the low end of proper psi (35-65 psi). Front tire...


...And rear tire. The hand pump might get it up to 50 psi with lots of sweating, but on the road I could get it this far in a few minutes...


The system looks like this now - switches in the up or 'A to B' position, split positives going to the phantom 25W solar panel and the phantom 100W solar panel...


The analog ammeter connected to the output control switch reads about 700mA going into the charging battery as the run battery reads almost double the amp draw...


This is the voltage reading of the two batteries while the ammeter is connected...

(02/29/20)

The previous fortnight spent discovering the practical operating parameters of the device has essentially answered my questions on maintaining battery charge under a light and a heavy load, how long before a 50W solar panel is needed, and the best switch rate...


The DC transfer switch added to the board for the 12Hr test...


Still from the very beginning of the short backup switch test video, showing the night light off...


Still from the very end of the short backup switch test video, showing the night light on. The backup 12V 7Ah battery powers the inverter just fine...


Fully charged batteries for the Fri. test...


Same here, but the system doesn't like both batteries being completely full...


The A battery bank voltage levels over five hours under the laptop load. The smartphone load showed unchanged voltage levels over three hours...

(03/18/20)

Since the lab's been on hiatus waiting for another power plant component, I spent most of the past fortnight wandering the camperbike weeds to decide what kind of bike living I want to do, which determines what and how to pack for it. Meanwhile the converters came in as I began production of the episode.


I found this 5A CC CV DC converter on sale from Hong Kong eBay and ordered two. This will work with 22Ah batteries...


One of my bikepacking bags - a trunk bag that sits on the rear rack, instead of a seat bag...


The side panels expand into panniers. The velcro straps underneath and in front attaches to the rack, and tie-downs secure the pannier bottoms to the rack frame...


The front velcro tie-downs. Total capacity of the bag is 22.6 liters/1380 cubic inches...


For coffee, I picked the small and lightweight GSI Coffee Rocket, a one-cup pour over unit that doesn't need a filter...


For most cooking, I just wanna boil water for instant meals or heat up canned goods, so I picked the Snow Peak Kettle No. 1 - 0.89 liters/about 30 oz. Aluminum, Japanese make...


As long as I'm taking a trailer for my sculpture gear and power plant, I can include a 5-gal. bucket and this Luggable Loo seat so I won't have to dig a cathole in the woods...


A rough cardboard mockup of the dimensions of the Schwinn Daytripper Cargo trailer - 27.00" x 23.50" outside, 23.00" x 19.50" actual cargo area minus 2" elbow room...


The 5A boost buck converters just came in. After wiping down the box it came in, my doorknobs and lock, and keychain, then washing my hands, I opened it up, took the doohickeys out, washed my hands again, then admired the components that have 10A fuses, not 5...