Anderson Powerpoles and DC Backup Power

You may recall from my last post the lovely photo of a large number of sealed lead acid (SLA) batteries gifted to me. I have finally completed the battery bank wiring with a few features in mind.

Originally I had 2x 2s2p 24VDC packs, and a 2s1p 24VDC pack, which I reconfigured to 1s10p.

I started out with this set of 7.2Ah, 12VDC SLA batteries and made up spade crimp terminal to powerpole adapters to allow for easy daisy-chaining of the batteries. I did this for a three reasons.

• Versatility – I can split off 1, 2, 3, 4 batteries to go power some other device without worrying about disassembling a static installation. Additionally I can change the physical arrangement of the batteries themselves (rectangle, single long string, over/under, etc.
• Compatibility – all my gear is fit with Powerpoles already
• Safety – I can make all my connections with a small capacity, then safely series them with connectors that will never allow a short (versus attempting to crimp a long dangly cable wtih 10 crimp connectors on it and connecting it carefully to ensure no shorts occur).

Related to the above 2 photos, I filmed a 2 part video on Anderson Powerpole connectors after I received my shipment from http://www.powerwerx.com

Vacation and Goodies Upon Return

So you may have noticed that I’ve been away for 2 weeks on a trip to Hong Kong/China, and a writeup of my travels is pending, but until then enjoy this photo of the goodies I have returned with.

The goodies:

1. KG-UVD1P hand held transceiver and spare battery with charger and car adapter (not battery eliminator)
2. 2x 4 position 2 axis joystick, 2x 2 position 1 axis joystick, 2x 2 position 1 axis joystick (momentary)
3. 2x CM300DY-24H IGBTs
4. Ultrafire C2 flashlight (single mode) with Cree Q5 emitter (200lumen approx), 2x 2400mAh protected batteries and charger
5. 12V 20A SMPS
6. Digital thermometer with K-type thermocouple (real cheap, only about <$8CAD for the whole kit with a case)

I also picked up a little ring of LEDs that approximately fits the lens adapter on my Canon S5IS camera, configured to run off of unregulated 12VDC, I plan to make a little battery pack and extension wire to let me do evenly lit macro photography without the normal lens-tube shadow that you’ve seen before in my photos. I need to laser cut an acrylic ring to get it to fit onto the lens tube as well (plus a diffuser), but more on that later. For now, a rough test shows that this idea works.

Yes, my desk is that dusty, especially after not touching it for 2 weeks.

Review of the Xantrex XPower PowerPack 400 Plus / Motomaster Eliminator 600 PowerBox

So I promised a review of this little bad boy, and here it is! Essentially the two products are the same, minus the labelling as Canadian Tire has a deal to rebrand a few Xantrex products including smaller and larger power packs.

In a nutshell, its main features are:

1. 12V, 20Ah sealed lead acid battery
2. 400W AC inverter (square wave)
3. Air compressor with short hose and fittings
4. Separate jumper cable for boosting low car batteries

On the road – aonomus rocks Virginia Beach

So I promised that I’d have something cool coming up, the major ‘secret’ project I’ve been working on is an Autonomous Surface Vehicle entered into a AUVSI competition. While I will eventually do a full writeup with pictures and descriptions of various hacks that we have done, and the general construction of the boat, however I’m to tied up with actually helping the team with getting the project complete and working for the competition.

The competition itself is held at Virginia Beach, at the Founders Inn hotel under the Association for Unmanned Vehicles Systems International. Starting on July 19th onwards, each night at 10pm the officials have said that a ‘recap’ video will be posted. As well, at some point there will be a live webcast set up… more details as they come.

In other news, I have finally popped my ham radio cherry while on this road trip. My friend had his FT-897 set up in the roadtripmobile with a 2m magmount antenna ontop of the van, I managed to make my first contacts as a ham on repeaters on the way down towards VA beach. Since his radio and mine (FT-857) are fairly similar with the multifunction display driven controls, it wasn’t terribly hard to make contacts, unfortunately there were issues with the power wiring to the radio, so my apologies to anyone that was speaking with me and got cut off.

To tide y’all over, pics are available here: http://s139.photobucket.com/albums/q297/aonomus/ASV/

Project Updates

So I’ve been busy over the last few days on a few projects.

First, a quick and simple wood frame for 3x 1W solar panels I purchased for $9 a piece. I plan to add a shunt controller, or at the very least a simple LM317 regulator set for 13.7-13.8V, because the solar panels are happy putting out a unloaded 23V!.

Yet another quick and dirty project, during my post-exam cleanup I decided I wanted to build a stand for my printer to sit on so that I can store stuff (ie: paper) underneeth it. Just old spare MDF from Ikea furniture. Always a good hack for anyone with flat pack furniture that they can’t be bothered to sell.

Another project that is unfortunately a bit of a failure is a big rackmount power supply I built. Using a beefy transformer it supplies 13.8VDC regulated, at high current (20-40A). Unfortunately the transformer I used was a microwave oven transformer, re-wound for low voltage. The transformer contains a shunt, and the laminations are welded together, shorting them and creating a ton of wasted power, and high idle current. Testing with a proper meter, I found out that the idle current is 6A, with a power factor of 0.12! Once I replace the transformer, the power supply should be rock solid and reliable.

Enough of that rant, the technical details:
The power supply uses 42000uF in the smoothing filter, 2x ISOTOP/SOT-227 dual diode modules for rectification, and 4x 2n3055 pass transistors with a LM723 regulator. The inside is a bit of a rats nest, however it works well and even *with* the voltage sag due to the transformer being very lossy, I can push at least 20A within a range of 12-14V. Note that using fuses is a very good idea with a power supply that has a very large short current, and the fuse block is mounted behind the front panel (those 2 screws on the right).

Future additions include: more binding posts, and a volt/current meter setup, along with the replacement transformer.

Last but not least, new gear! I’m studying for my amateurs license, and I’ve already picked up my radio, and a cheap (as in free) tuner.