T&L Publications

The biggest disadvantage of LiPo's is the fact that they are easily and almost always ruined if they become deeply discharged. You want to make sure that they never get discharged below about 3 volts/cell else they become garbage. I do not know if the tool makers have the units designed to prevent t...

Thanks to all who have replied. Since this is an old set and, since my first post, the buttons on the set itself started acting up (not responding properly if at all) I have just replaced the set with a new one. I had checked the battery connections on the old control module and they were fine (no a...

NiMh and NiCad are very similar in how they can be charged. The same charger can be used on either one; just, if peak detecting chargers are used, set the trip point for NiMh at about 5 millivolts while the NiCad can use about 10 millivolts. Now, if slow charging (being defined as charging at 0.1C) ...

I have an older (1992 vintage) TV that is still in good working order and used regularly. However, the controller is becoming very intermittent. Sometimes, when a button is depressed, nothing happens; i.e. it takes several presses on a button to have any effect. The batteries are not the problem, re...

What is the most common (and any suggested solutions) to why florescent lights do not turn on. I often have to switch the switch on/off several times before the lights go on. There are sometimes brief flashes as the switch is activated but the lights do not stay on. This seems to be worse as the wea...

Oh, what the heck .... I can help keep an old OP going. Anyone remember the Raytheon CK722? It was one of the most popular hobbyist transistors of the 1960s. You could get a bag of 10 of the things for a buck from Poly-Paks. 'Course, the Poly-Pak transistors didn't always work as advertised...... I...

I need to be able to determine if my 2.4GHz radio control transmitter is putting out an RF signal. No need to detect the modulation pattern, just is there rf out or not. The simple circuits I used for the 72MHz stuff doesn't seem to work, probably because my junk box does not hold any diodes capable...

In working primarily with NiCad but also NiMh, I have found there is no foolproof and FAST way to check out old batteries. The only reliable way I have found is to charge them at about 0.1C (that is at 1 tenth their capacity) for 15 to 16 hours. This insures that all cells are fully charged yet the ...

I have an old version of Borland's C++ (10 3.5 inch disks) but they will not load on Window XP. Do you know of any way to re install these disks or should I just junk them and look for a new C program? I have dropped out of the programming habit a few years back but am now interested in getting back...

That is one of the many nice things about Ubuntu, most devices are already covered with no need to search for drivers etc.

I have two 14 pin DIP chips made by NS with the part number KS20968L1 marked on them. I can not seem to find any info on them when I search the web. Can anyone tell me what they are and what the pin out is? Thanks.

I have two integrated 16 pin chips I am trying to identify as to function (data sheet hopefully) but can not find any reference to them by Googling or other searches. They must be a special order or very obsolete. Any info will be appreciated. They are stamped NS 20968L1 and seem to be a standard 14...

In general, this is not a good idea, especially if using polarized capacitors. Not only must the two capacitors be quite closely matched any heating caused by ripple currents can upset the balance. In some cases, paralleling each capacitor with a large value resistance will help with the voltage bal...

Is there a source for the physical shapes, sizes, key positions etc. for the various memory cards that plug into the typical desk top computer mother boards. A drawing showing the typical differences would be helpful.

I've used the Weller TCP series stations for 25 years. The tips have a thermomagnetic slug in the end that sets the temperature by cycling a magnetic switch in the handle. Several heat values and a wide range of tip sizes are available. In all the years I've repaired the irons several times and it ...