Reloaded HASH and battery works

After weeks of wasting our Saturdays on valuable cultural visits to temples, historical sites and bakeries with half off cakes, we made it back to the HASH for a strenuous and beautiful run. However, the rare event of the day was our dinner at the famous Fire & Ice restaurant, one of the most expensive ones and the one with the best pizza in Kathmandu. The scene was set by our view of two Buddhist monks, dressed in their dark red garments, sitting at a table at this expensive restaurant eating pizza by candle light.

Clarification, the HASH does not refer to the consumption of illicit herbal medicine, but to an event where a large group of wonderful people get together to run under a set of pre-established rules. Hash House Harriers, google compatible.























The week started with the assignment to start building as many PowerCentres as we can, aiming at 20. The PowerCentres are the boxes encasing the 12V lead acid batteries that contain circuitry to protect the battery against overcharging, charging too quickly, discharging too much and has a little display that shows how charged the battery is. These devices are connected to the PedalPower in order to charge the battery or the small 6V batteries in their UserBox are connected to the PowerCentre to charge the 6V battery. You can also plug lights and other devices directly to the PowerCentre.


















My focus over this task was getting the UnderVoltage Protection to work. This is the protection against over discharging; if the battery is discharged more than it should be, the voltage across the battery will drop and the UnderVoltage Protection will interrupt current between the battery and whatever device was draining the battery. The problem was that those that were assembled already were either not interrupting the connection at all or doing it at undesired voltages (we are aiming at 11.3-11.5V). But after days of testing component by component and evaluating at what voltage each of the Zener diodes interrupts current (there is an uncertainty to the value they claim to have for Zener voltage, so the individual zener voltages will vary by +/- 0.5V) I managed to fixed some of them and build a few new ones.

Most of the week also carried an overwhelming expectation for Thanksgiving for the 20 or so people that attended the dinner at Rosie's flat on Thursday. Friends of friends were included in the emailing list, gate crashers were welcomed and the gathering ended up containing a large group of people that didn't know each other. So was the fantastic collection of people that we managed to gather, without previously knowing, an additional Dartmouth alumnae who is working in Kathmandu, Arthur McKeown '97. Unfortunately, is nearly impossible to find turkey in Kathmandu, so Katherine Ensler did an excellent job with 2 whole chickens instead. That, with the traditional cranberry sauce and an exquisite gravy left everyone deeply satisfied. Ultimately it was the pies, apple pies, pumpkin pies and a delicious carrot cake of my creation, that really stuffed the attendees.