Friday, 1 January 2016

New Year project work

Well, its now next year! 2016 started just 20 minutes ago, so if your mad enough to be reading this and now getting off yer 'ead, happy new year,

Ive a whole stack of things I need to finish off before getting onto any new projects. Unfortunately thats not how it works, and new projects present themselves, as do urgent repair jobs. So, having spent much of new years eve carrying out emergency repairs to fencing, I started by finally getting the speaker sound holes drilled and the speaker mounted to finish off the Chinese airband radio

The only problem is, with the speaker fitted and lid on, the tuning range has gone to pot! Some more adjustment needed I think to the VFO coil. I might introduce an adjustment hole in the lid!

I also got around to trying out the multi-chemistry battery charger, starting with a big 24v NiCd pack for the Clansman radios. This was more an exercise in finding my way around the controls and menus without the risk of doing so with a Lithium pack attached!

Whilst this was running, I progressed some on the LiPo rebuild of the metal cased Clansman battery. The first task was to connect the charger/balancing/activation/protection connector (a 25way D connector) to the LiPo monitor/low voltage alarm.

As you can see, im taking NO chances with this! A short would be catastrophic, so every wire gets heatshrink sleeving. Black for 0v, orange for the HT end, and red for the other cells.

The left hand eight connections of the top row of the connector are wired to the monitor unit. The lower left hand eight are wired to the two balance connectors for the battery. This leaves nine pins spare. Three of these will be wired to an LM35 temperature sensor attached to the battery.

As is, the battery will operate regardless of whether there is anything attached to this socket. But it will not be monitored or protected. A 25way male cable will connect the balancing ports of the battery to the balance ports on the charger, and also the temperature sensor input.

A second male connector acts as a 'personality' plug. Initially, this will simply connect the balance connectors to the monitor module. This will allow me a visual and audible warning of battery level. Should I decide that an active low voltage cut off is needed, this plug will allow me to access the protection circuit to set/reset the trip.

 Next stage then is to cut out a hole for the LED display to be visible, attache the temperature sensor to the battery and the connector, and to fit and mount the battery inside the housing. I also need to make up the balance charger cable.

I also have on my list to repair both my Rogers Ravensbrook tuner/amp, and my Ferranti U1032 valve table set. Ive also a ignition switched 12v - 5v DC-DC converter to install in my car along with cabling to give me a suitable USB power connection for my new dash cam. These will be the main electronic projects for a while.

No comments: