Tuesday, October 26, 2010

Engineering Notes 1

H/Motel Spigots and Faucets
Generally, for a sink, shower or other wet area that requires water of varying temperatures one will install either two spigots mixing into a single faucet or a single "mixer" spigot and one faucet (these last two may be integrated). I'm ignoring the older style of two spigots and two faucets.

These two setups allow control of two oupts via two control inputs. Either:
  1. Temperature (T) and Flow (f) via Hot flow (H) and Cold Flow (C)
  2. Temperature (T) and Flow (f) via Hot/Cold Ratio (r) and Flow (f)
However many motels here seem to have gone a different route - simplify things for the guest by denying a variable, aka a mixer spigot with only one axis of rotation (off, then rotation from cold to hot). Indulge me in my MatLab presentation. Let's assume the hot source is 80degC and the cold 10degC. This leads to:
Normalising all input variables to the range [0,1] we can create the following:

Or as contours:
In any case, the bottom line is the hotel picks the flow (and it's generally pretty high, I prefer falling water over jets) and you don't get that "spiral staircase" (see contour) temperature discontinuity as you would with traditional home-brew water management

Jump for code...

Side Notes 1

Item 1: Automotive light systems
While Japanese-made and European-made cars on the whole seem to maintain the standards observed elsewhere in the world (aside from metric/imperial/US debates). However, locally-made vehicles often seem to exhibit the following symptoms:
  • Red indicators on the rear of the vehicle. Often these indicators are in fact the brake light (single side) activated through an indicator switch circuit
  • Indicators being activated as headlights (but still alternating for turning). They seem to replace the "park" lights at the front.
Item 2: Rotational light switches
I have to admit I tried a few things with these switches before I figure it out (pretty much all dimensions of force and a couple of rotation). Light switches with every 90deg rotation. I have also seen one fancier one to switch two lights - still every 90deg (Off-A-B-AB-Off).

Item 3: Toilets
The ones here seem to have significantly more water in the bowl. That is all.

LA to San Diego


This started with another pedestrian expedition, but this time to acquiesce to LA's preferred form of transport. I stopped nearby for a McDonald's breakfast (when in Rome?) but this wasn't really my first mistake. That was ordering the McGriddle. I just don't think I'm onboard with the American palate of sweet and salty. In short, a sweetened pancake with maple(like)-syrup was not what I wanted with bacon and eggs - they are just fine salty.

Skipping over some admin, organisation and packing I started to head for San Diego - but I thought it was important to go via Santa Monica (excuse the bleached hair and bad guitar mime), and Hollywood/Beverly Hills, and even more important to stop into Wal-Mart for the cheap GPSs available and recommended by Tien Mun (Indeed: $99, about 2/3 the cost of a new set of maps in Australia.)

Apart from checking a few recognisable place names off the list (eg Sunset Bvd) the most impressive place was the Hollywood hills - Jalmia Drv was the road I got to. I couldn't resist all the very squiggly lines on the GPS so I just drove until I got to a dead end. Lovely shady trees, windy roads, tight squeezes past UPS vans and vehement "no trespassing" signs were all beheld.

And then... to San Diego for a sleep.

The lack of photos until now is mainly evidence of the difficulty in photojournalism when:
- on roadtrip
- there are a lot of "No Parking" zones
- there is no accompanying BBC crew


LA, to be honest, never received too much of my attention. I had very little sleep while tidying up loose ends in Melbourne, and probably slightly less on the flight. Hence I didn't deal very well with arriving 4 hours before I left yet stunningly more tired.

Still, as it was morning and check in wasn't for a while I decided to go shopping for some basics. After leaving my bags in the Culver City hotel I headed for the Westfield centre I was told was nearby. I was aiming for sandals (due to how badly my feet were dealing with the heat in my hiking boots), groceries, SIM for my phone and general groceries to keep food costs down.

I headed for target for item one, and found that they seem to do groceries there too. That, and end-of-season sales meaning 75% off sandals from a 50% off price meant I did fairly well there. On the phone front, today was the first step of many in struggling to find phone dealers (and departments in department stores) who understood the concept of an unlocked phone/prepaid phone use and most importantly actually stocked SIM cards.


Essentially, due to the fact that traveling doesn't allow much time for writing and recording I took brief notes daily I hope to decompress them here.

First up is California...

(Oh yeah, and click headings of traveling posts for google maps recordings. You should see a tinyurl on mouseover - not this post.)