Home
Help
Search
Login
Register1
Test Equipment / Re: Siglent SDS2000X HD, 12bit, 2GSa/s high definition oscilloscope serie.
« Last post by KungFuJosh on Today at 12:43:25 am »However that HW has increased in price.
The homebrew version still works. 😉
Recent Posts
The homebrew version still works. 😉
2
Test Equipment / Re: Problem with my scope? Reading positive versus negative average DC voltages.
« Last post by tautech on Today at 12:40:11 am »Dunno, a while ago closed the datasheet tab.I agree that 3% deviation would be more than expected for a reputable scope.Cough.
+ 3% vertical accuracy has been industry standard for decades but now improved near 10x with the advent of cheap 12bit DSO's.
Spec from the datasheet for the DSO OP uses is:
DC vertical gain accuracy:
+3% full scale (≥ 10 mV/div)
+4% full scale (< 10 mV/div)
What's the spec for crosstalk between channels?
Easy to find though.....
3
Test Equipment / Re: Siglent SDS2000X HD, 12bit, 2GSa/s high definition oscilloscope serie.
« Last post by tautech on Today at 12:37:50 am »So I am in the market for a scope in the running is the DHO 914S but the bode plots and LA suck so this one is a non starter. The DHO 1000 is sexy but that is all it is, has no MSO options, and no bode plot. So I was looking at the SDS1104xHD and that is checking all the boxes, but the non integrated perhiprials suck no built in AWG, and external LA function is probably not going to satisfy my mixed signal needs entirely. Then the SDS2204xHD is checking the boxes bit more pricy than I want to spend but, decent equipment is never cheap. So what do you SDS2000xHD users think is the extra money worth it, and do I have to pay for software licensing for the AWG, and the LA functions besides buying the probe kits.No.
SW licensing for all/any external AWG/LA HW has been removed in recent firmware.
However that HW has increased in price.
4
Manufacturing & Assembly / Which silkscreen colour has best visibility
« Last post by Wilson__ on Today at 12:37:35 am »Which silkscreen colour is easy to see and position components during soldering?
Have not seen Yellow, White, Purple and Matte green. Are they good? May be bright colours have better contrast with dark/black chips?
On hand have Green, Red, Blue, Black. Red is best in four.
Many thanks
Have not seen Yellow, White, Purple and Matte green. Are they good? May be bright colours have better contrast with dark/black chips?
On hand have Green, Red, Blue, Black. Red is best in four.
Many thanks
5
Thermal Imaging / HT-203U VS TOPDON TC002C ?
« Last post by mikeee on Today at 12:37:14 am »Long time lurker first time poster. I have been getting really deep in electrical repairs and am looking for a hobby use Thermal imaging camera. I am looking to spend around $200 us dollars and seem to be stuck on the HT-203U unbranded or the topdon TC002C? I have android and apple products so that not an issue. I have had a topdon product and their customer service was no existent. Or is there another camera you guys recommend? Thanks Mike
6
Test Equipment / Re: Problem with my scope? Reading positive versus negative average DC voltages.
« Last post by Fungus on Today at 12:36:00 am »I agree that 3% deviation would be more than expected for a reputable scope.Cough.
+ 3% vertical accuracy has been industry standard for decades but now improved near 10x with the advent of cheap 12bit DSO's.
Spec from the datasheet for the DSO OP uses is:
DC vertical gain accuracy:
+3% full scale (≥ 10 mV/div)
+4% full scale (< 10 mV/div)
What's the spec for crosstalk between channels?
7
The AmpHour Radio Show / Re: Chris live streaming?
« Last post by oPossum on Today at 12:35:02 am »8
RF, Microwave, Ham Radio / Re: CB and Ham Radio Techs Love Their Bird Wattmeters
« Last post by pdenisowski on Today at 12:34:37 am »... we have quite a few hams working for Rohde & Schwarz, including Dr. Rohde himself (N1UL).
That must have come as a shock to [people] posting in this thread.
He's been in QST numerous times in the last couple of years. He's also donated a lot of very nice instruments (like a vector sig gen and a phase noise analyzer) to the ARRL labs.
9
Projects, Designs, and Technical Stuff / help with reducing consumption for very small motor / low voltage buck
« Last post by pommil on Today at 12:33:29 am »Hi,
I'm trying to get a small dc motor to run for the longest possible time from the energy of a small solar panel with a liion battery (or cap). The solar panel output up to 40mA at 0.5v (close to max max power point). I have tested the motor, it starts at 0.142v/11mA (I can also do 24mA and 270mV).
I'm using a bq25570 energy harvester on a board from aliexpress https://fr.aliexpress.com/item/1005006447191303.html?spm=a2g0o.productlist.main.7.1dc16677O5KYPj&algo_pvid=6fcbbdd6-e42e-49dd-975f-6771b66e1efa&aem_p4p_detail=202409241648145856548259165120010910300&algo_exp_id=6fcbbdd6-e42e-49dd-975f-6771b66e1efa-3&pdp_npi=4%40dis%21EUR%2114.99%2114.99%21%21%2116.26%2116.26%21%402103868817272216948587324e340f%2112000037202243228%21sea%21FR%21760932160%21X&curPageLogUid=x5iwhs9uLGKZ&utparam-url=scene%3Asearch%7Cquery_from%3A&search_p4p_id=202409241648145856548259165120010910300_1
It's basically dealing with the battery management, energy harvesting and outputting 2.6v (100mA max).
I want the motor to run as slowly as possible to reduce it's power consumption. So, I have 2.6v and need to reduce it to approx 0.2. I could not find a suitable buck (I'm trying to avoid smd component so can't use something like ADP5331 and anyway, it's still cannot go under 0.8v).
I have tried an astable multivibrator to PWM the motor and reduce its power consumption. It's working fine to reduce the motor speed and I can get it down to 11mA and 142mv, but the problem is that the circuit consumes 11mA at 2.6v! 11 mA are going through Q3 with 142mV for the motor and the rest between Q3 and ground (about 2.56V*11mA). I have tried playing with capacitor and diode, but can't solve it. From my readings, it seems I may need to add an inductor somewhere??
Or should I feed back the excess voltage inside the BQ2550 (connecting emitter of Q3 and ground to + and - of solar cell, but then I'll have to add a diode on the solar cell, possible but not sure it would work and don't really want the voltage drop of the diode + it may mess up the MPPT of the BQ25570).
Thanks in advance for any suggestion, either:
- on the overall idea of BQ25570 + SOLAR + BUCK / PWM + LIION BATT + DC MOTOR
- on how to reduce the power consumption of the multivibrator (kind of turning it into a buck?)
- on what other solutions to efficiently reduce motor consumption with through hole if poss)
- on any good low voltage buck on a board or SMD if nothing else
Thanks a lot in advance
I'm trying to get a small dc motor to run for the longest possible time from the energy of a small solar panel with a liion battery (or cap). The solar panel output up to 40mA at 0.5v (close to max max power point). I have tested the motor, it starts at 0.142v/11mA (I can also do 24mA and 270mV).
I'm using a bq25570 energy harvester on a board from aliexpress https://fr.aliexpress.com/item/1005006447191303.html?spm=a2g0o.productlist.main.7.1dc16677O5KYPj&algo_pvid=6fcbbdd6-e42e-49dd-975f-6771b66e1efa&aem_p4p_detail=202409241648145856548259165120010910300&algo_exp_id=6fcbbdd6-e42e-49dd-975f-6771b66e1efa-3&pdp_npi=4%40dis%21EUR%2114.99%2114.99%21%21%2116.26%2116.26%21%402103868817272216948587324e340f%2112000037202243228%21sea%21FR%21760932160%21X&curPageLogUid=x5iwhs9uLGKZ&utparam-url=scene%3Asearch%7Cquery_from%3A&search_p4p_id=202409241648145856548259165120010910300_1
It's basically dealing with the battery management, energy harvesting and outputting 2.6v (100mA max).
I want the motor to run as slowly as possible to reduce it's power consumption. So, I have 2.6v and need to reduce it to approx 0.2. I could not find a suitable buck (I'm trying to avoid smd component so can't use something like ADP5331 and anyway, it's still cannot go under 0.8v).
I have tried an astable multivibrator to PWM the motor and reduce its power consumption. It's working fine to reduce the motor speed and I can get it down to 11mA and 142mv, but the problem is that the circuit consumes 11mA at 2.6v! 11 mA are going through Q3 with 142mV for the motor and the rest between Q3 and ground (about 2.56V*11mA). I have tried playing with capacitor and diode, but can't solve it. From my readings, it seems I may need to add an inductor somewhere??
Or should I feed back the excess voltage inside the BQ2550 (connecting emitter of Q3 and ground to + and - of solar cell, but then I'll have to add a diode on the solar cell, possible but not sure it would work and don't really want the voltage drop of the diode + it may mess up the MPPT of the BQ25570).
Thanks in advance for any suggestion, either:
- on the overall idea of BQ25570 + SOLAR + BUCK / PWM + LIION BATT + DC MOTOR
- on how to reduce the power consumption of the multivibrator (kind of turning it into a buck?)
- on what other solutions to efficiently reduce motor consumption with through hole if poss)
- on any good low voltage buck on a board or SMD if nothing else
Thanks a lot in advance
10
General Technical Chat / Re: The nightmare reality price of cars now tracking and selling your every move.
« Last post by BrianHG on Today at 12:30:30 am »And about insurance, it's a question of whether you want a cheaper deal by letting them monitor you.You got it backwards. My rates are already cheap. Monitoring you gives the insurance company an any time valid reason to increase your rates. My rate would not go lower the moment I get a car with monitoring.
The monitoring helps insurance companies increase their bottom line, not give their clients a better deals.