| Country | italy |
| Note | microprocessor for hobby. I 'have electronics magazine in Italian language. |
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81
on: August 23, 2024, 07:12:26 19:12
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| Started by rommel100 - Last post by rommel100 | ||
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82
on: August 22, 2024, 08:26:53 08:26
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83
on: August 21, 2024, 08:14:10 20:14
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| Started by EL45 - Last post by JD22 | ||
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Thank you for invitation. Registration is done.
Note: This message sent by the system behalf of JD22. |
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84
on: August 21, 2024, 08:09:39 20:09
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| Started by EL45 - Last post by Sideshow Bob | ||
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This member is invited by me. Registration isn't completed yet.
Note: This message sent by the system behalf of Sideshow Bob. |
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85
on: August 21, 2024, 07:47:00 19:47
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86
on: August 18, 2024, 10:27:10 22:27
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| Started by PM3295 - Last post by PM3295 | ||
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So I found a 1 GHz fet probe that only works on our Lecroy scope. This has only 1.8 pF of loading.
After connecting this up, it showed terrible oscillations around 550 MHz! One way of damping this, is to use a suitable ferrite bead. I inserted two small beads in the leg shown in the updated circuit. This worked very well. The only remaining impulses seem to be coupling through from the strobe node and is of fewer concerns. The lesson is, if you see strange behavior, your scope's limited bandwidth may be hiding bigger problems! |
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87
on: August 18, 2024, 05:38:35 17:38
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| Started by PM3295 - Last post by PM3295 | ||
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Did some more work on this and modified the circuit by placing a 2.7 ohm in series with C1. This caused some instability, and I had to place another 1 nF (C4) in parallel with this resistor to quiet things down. This largely reduced the final settling value error for both 1 V and 2 V pulse inputs. There is still some ringing regardless of my best probing attempts under these conditions. I will have to try using a fet input probe with minimal loading later to see if it reduces the ringing. This node seems very sensitive to probe tip loading.
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88
on: August 18, 2024, 04:48:54 16:48
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| Started by PM3295 - Last post by PM3295 | ||
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Found this interesting video from the VintageTek Museum to get the most out of these scopes.
https://www.youtube.com/watch?v=LvTjTBDYCf4 |
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89
on: August 18, 2024, 09:12:19 09:12
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| Started by sadman - Last post by bobcat1 | ||
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Hi
555 can only drive/Sink 300mA so you need carefully choose the Mosfet you drive Far more easy to use dedicated Mosfet driver who can drive more powerful Mosfet All the Best Bobi |
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90
on: August 17, 2024, 09:06:44 21:06
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| Started by PM3295 - Last post by PM3295 | ||
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So I got around getting the TLV3601 and build up a test board.
The measured results look very good. There is some disturbance on the measured yellow trace most probably caused by the scope probe on this sensitive node. The green trace is from the function gen terminated in 50 ohms. Update: After finding a suitable spring clip for the probe to reduce parasitics, the waveform looks much cleaner. I also scoped the strobe pin showing rise/fall times close to the data sheet spec of 2.5 ns. |
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