Joule Thief

[freepow]

The Vellemen  handheld digital oscilloscope has a sampling rate of 10 Ms/s & up to ? vdc ,$300
      UT81B     handheld digital oscilloscope has a sampling rate of 40 Ms/s & up to 1000vdc ,$263
      AHJ 6104 handheld digital oscilloscope has a sampling rate of 50 Ms/s & up to 1000vdc ,$214





                             

[MrMag]

I agree totally. I followed MrMag's recommendations a while back and found and obtained a Tektronix model 2213 60 mhz dual channel scope with manuals and got 2 new probes on Ebay for $150.00 total.  Best purchase I ever made.  This is a very good quality instrument and works very well.

Of course, I am still learning how to use it properly but, I am getting there.

Bill

[resonanceman]

The Vellemen  handheld digital oscilloscope has a sampling rate of 10 Ms/s & up to ? vdc ,$300
      UT81B     handheld digital oscilloscope has a sampling rate of 40 Ms/s & up to 1000vdc ,$263
      AHJ 6104 handheld digital oscilloscope has a sampling rate of 50 Ms/s & up to 1000vdc ,$214

Thanks freepow

Here is one I have been looking into.
I am checking on its max input voltage......I see input protection is diode clamping......If I understand that right .....any voltage over the  clamping voltage will  be drawn  off....... That sounds like a good idea to me.

I  found out about this on another thread.... gotoluc  has one  and  likes it.....

http://cgi.ebay.com/DSO-5200-50GS-S-PC-USB-digital-storage-oscilloscope_W0QQitemZ140324893670QQcmdZViewItemQQptZBI_Oscilloscopes?hash=item20ac03f3e6[/quote]


gary






                             

[conradelektro]

To all who look for a tool to measure Joule Thieves:

I got the DSO-2100 USB PC USB Digital Storage Oscilloscopes which is not sold any more (it is about 4 years old) and it helps me a lot. It would be very boring without it.

The newer model DSO-5200 (resonanceman posted it) is a very good choice today, or that one: http://www.hantek.com.cn/english/produces.asp (DSO 2150). Hantek manufactures these oscilloscopes in China and they are sold by various distributors.

Attached two scope shots I did today with my DSO 2100. The point is, that one can see the  most complicated wave forms very nicely.

It is very helpfull to buy a x100 probe (in addition to a x1 and x10 probe), which I use to measure signals up to 3500 Volts.

On the attached scope shots you see a measurement over the secondary of a joule thief that gives about 600 Volts (air coil).

It is quite easy to use my DSO 2100, although one can get missleading results as a beginner. The probes I got prevented all disasters because they have a high impedance (resistance). Sometimes I do not understand the measured result because I do not understand the interaction of the scope probe with the circuit, specially when I measure high frequency signals. Sometimes the circuit stops working when I attache the scope probe (also an interaction of the probe with the circuit). But I am getting better at it.

I like very much that the scope on the USB port of my PC allows storage of the measurements as images which I can recall later. A drawback is that one needs a PC or Laptop to use the scope.

Best would be a stand alone DSO which can also be connected to a PC (but that costs several thousand Euros).

Greetings, Conrad

[MrMag]

@Conraddelektro,

Nice scope shots. That's the BIG advantage of the PC interface systems. I have a feeling that my next scope will be one of these units. I just don't feel comfortable with the handheld units. (Unless you buy one of the more expensive units)