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Microcontrollers / Re: Looking for information on TEST pin and ways to DUMP mask ROM of PIC1650 PIC16xx
« Last post by woofy on Today at 09:23:21 am »The only info on the test pin I have says "Test input not normally used".
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Projects, Designs, and Technical Stuff / Re: role of optocoupler for biasing drain of amplifiers
« Last post by xvr on Today at 09:21:45 am »> You said i should put a zenner diode .
did you meen in parralel to the power supply?
No. In series with R2 in my schematic
As for temperature raise, it calaculated as power, dissipated in MOSFET multiplayed by Temperature resistance (55W/C by your calculations). Power dissipation is I^2*Rdson
Graph in question shows changes of Temperature resistance via pulse characteristics.
Tja & Tjc are temperature resistancies from chip junction to ambient (this is case of bare chip in air) and for chip junction to case (this is variant of chip attached to ideal heatsink)
As you understand there is no such thing as ideal heatsink, so in later case you shoul add Temperature resistance of heatsink itself to Tjc to get real value
did you meen in parralel to the power supply?
No. In series with R2 in my schematic
As for temperature raise, it calaculated as power, dissipated in MOSFET multiplayed by Temperature resistance (55W/C by your calculations). Power dissipation is I^2*Rdson
Graph in question shows changes of Temperature resistance via pulse characteristics.
Tja & Tjc are temperature resistancies from chip junction to ambient (this is case of bare chip in air) and for chip junction to case (this is variant of chip attached to ideal heatsink)
As you understand there is no such thing as ideal heatsink, so in later case you shoul add Temperature resistance of heatsink itself to Tjc to get real value
3
Projects, Designs, and Technical Stuff / Re: a high side load switch made from n channel and p channel mosfet working princip
« Last post by moffy on Today at 09:18:48 am »When 'enable' is low then Q1 is 'off', and the gate of Q2 is pulled up to its source by R2 and it too is 'off'. When 'enable' is high then Q1 is 'on' and the gate of Q2 is pulled down to 0V turning Q2 'on'.
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Jobs / Re: Contract Job - EEVblog: Making Shorts/Reels
« Last post by Exwallid on Today at 09:18:39 am »Your post about the contract job opportunity at EEVblog is like music to my ears! It's fantastic to see opportunities like this pop up, especially in a community where talent and expertise are valued.
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EEVblog Specific / Re: EEVblog 1612 - Siglent SDS1000X HD 12 bit Oscilloscope Teardown
« Last post by golden_labels on Today at 09:13:10 am »While going frame by frame, you can see that the 2354 updates on each frame, while the 1024 usually displays a single waveform for 2 frames.
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3D printing / Re: could anyone please print me a microscope Head adaptor ring
« Last post by davebb on Today at 09:09:33 am »Today The post women had my adaptors from mendip_discovery,Thanks Again,
The Adaptors fit very well, it is a shame that the ABS one failed half way through as it is a tighter fit with the ali spacer, but the other is fine just a little bit more play but still very good, why i wanted the long size is to hold the LED Ring Light,
if i mount the ring light to the lens i can use the ABS Adaptor, i am very happy with your great work Roger,
Thanks Again,
Dave 2E0DMB
The Adaptors fit very well, it is a shame that the ABS one failed half way through as it is a tighter fit with the ali spacer, but the other is fine just a little bit more play but still very good, why i wanted the long size is to hold the LED Ring Light,
if i mount the ring light to the lens i can use the ABS Adaptor, i am very happy with your great work Roger,
Thanks Again,
Dave 2E0DMB
7
Beginners / Re: Quickly Triggering Sensors - need an oscilloscope? what specs? (AU)
« Last post by xvr on Today at 09:06:25 am »Sure, if you can find one - it's obsolete by Discovery 3
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Microcontrollers / Re: Divide clock by 3 on a ATF16V8B
« Last post by xvr on Today at 09:04:25 am »Main problem with 16V8 not a possibility of implementing something with it, but possibility to program it. It requires special hardware to program, and programming specifications is not publicaly available (official).
So, if you do not have access to some PLD programmer using 16V8 is a very problematic
So, if you do not have access to some PLD programmer using 16V8 is a very problematic
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Microcontrollers / Re: How to create custom bootloader in esp8266
« Last post by digitalectron on Today at 09:03:40 am »Quote
There are several Arduino wrappers for OTA systems for the 8266. They mostly work OK. For example the OTA for the Tasmota project is very reliable and uses multiple partitions with fall back so if it fails it's no big deal to just try again, not having to resort to connecting the USB up and flashing it via serial.
Thanks for your help , How do I find the best link for Tasmota project?
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RF, Microwave, Ham Radio / Re: Cascade RF Frontend 2.4GHz possible?
« Last post by Flunze on Today at 09:01:10 am »Hi vk4ffab. Thanks for your reply. But I think you overread something:
This means the Backend outputs around -65dbm and the first stage -40dbm. I mean, if I would have +5dbm why would I bother amplifying anything? I have no way to directly measure this however. It is possible, that my phone is not really the best. But the manufacturer claims at most 100mW of output power (consisting of 4 channels). Originally I measure however -20db. Okay lets do some simple math:
The 20dbm in total for a single channel are 14dbm for the original circuit. My phone measures -20dbm (a lot of loss, but very repeatable measurements with multiple devices). Okay, I measure -40dbm with a single of the replacement Frontend IC's. That is 20db lower, so +14dbm-20db = -6dbm. This is well within range of what the input of these ICs can handle according to the spec.
Okay, this clearly shows that the -65dbm at the beginning are incorrect, but it backs up that I have 1 order of magnitude of safety left. That also means, that if it works, the output power basically lands right in the perfect spot of +20dbm. That would actually be absolutely amazing.
My question is just, if you look at the circuit: Can you chain 2 of these ICs in series, or do you need some passives in between? Remember, I do not look for perfect performance at all. It just needs to work reasonable for a low effort. I would think, that the Output is basically at DC level, just like the input - so I would think it should be fine. All circuits use 3.3V as input, so I expect the voltages to be at equally fine levels.
TLDR:
- Input power is definitely within safe range
- Question: Do I absolutely need some passives or could a direct ANT Out to RXTX work with a direct connection? (ignore impedance and parasitics for now)
Quote
Without this I get -65dbm and with about -40dbm
This means the Backend outputs around -65dbm and the first stage -40dbm. I mean, if I would have +5dbm why would I bother amplifying anything? I have no way to directly measure this however. It is possible, that my phone is not really the best. But the manufacturer claims at most 100mW of output power (consisting of 4 channels). Originally I measure however -20db. Okay lets do some simple math:
The 20dbm in total for a single channel are 14dbm for the original circuit. My phone measures -20dbm (a lot of loss, but very repeatable measurements with multiple devices). Okay, I measure -40dbm with a single of the replacement Frontend IC's. That is 20db lower, so +14dbm-20db = -6dbm. This is well within range of what the input of these ICs can handle according to the spec.
Okay, this clearly shows that the -65dbm at the beginning are incorrect, but it backs up that I have 1 order of magnitude of safety left. That also means, that if it works, the output power basically lands right in the perfect spot of +20dbm. That would actually be absolutely amazing.
My question is just, if you look at the circuit: Can you chain 2 of these ICs in series, or do you need some passives in between? Remember, I do not look for perfect performance at all. It just needs to work reasonable for a low effort. I would think, that the Output is basically at DC level, just like the input - so I would think it should be fine. All circuits use 3.3V as input, so I expect the voltages to be at equally fine levels.
TLDR:
- Input power is definitely within safe range
- Question: Do I absolutely need some passives or could a direct ANT Out to RXTX work with a direct connection? (ignore impedance and parasitics for now)