| ??? 06/25/05 02:11 Read: times |
#95891 - Already Responding to: ???'s previous message |
I've tried the filter circuit already, the one below the two you have given me to try. I use a signal generator to generate frequency from xxHz to 100kHz. By investigating its output by a scope it doesn't show a filter characteristic.
It seems to me that the problem is the signal is too weak, together with noise. Both are 40kHz. The LM567 is optional. After amplifying, I can use either a comparator or the LM567. Stanley |
| Topic | Author | Date |
| Ultrasonic Signal Processing | 01/01/70 00:00 | |
| Time dependant gain | 01/01/70 00:00 | |
| Further attenuation... | 01/01/70 00:00 | |
| Signal recovery. | 01/01/70 00:00 | |
| AGC? | 01/01/70 00:00 | |
| AGC as Steve said// | 01/01/70 00:00 | |
| My Algorithm was: | 01/01/70 00:00 | |
| My Algorithm was: | 01/01/70 00:00 | |
| Ultrasonic Ranging | 01/01/70 00:00 | |
| Matched filter on the rescue | 01/01/70 00:00 | |
| matched filters | 01/01/70 00:00 | |
| Phase locked amplifier | 01/01/70 00:00 | |
| Its a different thing | 01/01/70 00:00 | |
| Ah | 01/01/70 00:00 | |
| Thats the one.... | 01/01/70 00:00 | |
| Clever woman | 01/01/70 00:00 | |
| Just an idea | 01/01/70 00:00 | |
| The scope plot tells it all! | 01/01/70 00:00 | |
| Largest signal | 01/01/70 00:00 | |
| 'Greatest' echo is the wrong criterion! | 01/01/70 00:00 | |
| | 01/01/70 00:00 | |
| somehow I remember... | 01/01/70 00:00 | |
| No, no... | 01/01/70 00:00 | |
| Oops~ forgot... | 01/01/70 00:00 | |
| the product | 01/01/70 00:00 | |
| Power of transmission pulse | 01/01/70 00:00 | |
| Preamp circuit Here | 01/01/70 00:00 | |
| Add caps to remove base line noise | 01/01/70 00:00 | |
| Another potential problem... | 01/01/70 00:00 | |
| Problem with ADC? | 01/01/70 00:00 | |
| possible solution to the ADC problem | 01/01/70 00:00 | |
| Ok~ | 01/01/70 00:00 | |
| Debug Result | 01/01/70 00:00 | |
| ADC Sampling and code debugging | 01/01/70 00:00 | |
| sampling time | 01/01/70 00:00 | |
| Adc for Ultrasonic? | 01/01/70 00:00 | |
| Next, comes to "average" | 01/01/70 00:00 | |
| Why use the adc? | 01/01/70 00:00 | |
| Forgot to tell... | 01/01/70 00:00 | |
| Circle in RED | 01/01/70 00:00 | |
| Asking for help again - Filter | 01/01/70 00:00 | |
| Notch | 01/01/70 00:00 | |
| I don't know | 01/01/70 00:00 | |
| DSP | 01/01/70 00:00 | |
| Nah | 01/01/70 00:00 | |
| for the sake of learning | 01/01/70 00:00 | |
| so | 01/01/70 00:00 | |
| I agree | 01/01/70 00:00 | |
| Amplitude | 01/01/70 00:00 | |
| Op amps | 01/01/70 00:00 | |
| 100pF | 01/01/70 00:00 | |
| bypass ?? | 01/01/70 00:00 | |
| Yes | 01/01/70 00:00 | |
| No sort of bypass | 01/01/70 00:00 | |
| BTE054 BTE054USS2 | 01/01/70 00:00 | |
| Better noise control | 01/01/70 00:00 | |
| re: BTE054 | 01/01/70 00:00 | |
| Replace LMV6032 with LM324 | 01/01/70 00:00 | |
| re:low sensitivity | 01/01/70 00:00 | |
| re:no filtering | 01/01/70 00:00 | |
| Note | 01/01/70 00:00 | |
| Notch filter? | 01/01/70 00:00 | |
| No, | 01/01/70 00:00 | |
| Bandpass | 01/01/70 00:00 | |
| NOT a criticism | 01/01/70 00:00 | |
| Update... | 01/01/70 00:00 | |
| Umm... Nowadays? | 01/01/70 00:00 | |
| Op amp parameters | 01/01/70 00:00 | |
| "Filters for Dummy" | 01/01/70 00:00 | |
| Have you tried it with ..... | 01/01/70 00:00 | |
| Yes, I've tried it and it works well | 01/01/70 00:00 | |
| Basic electronics | 01/01/70 00:00 | |
| 0.002uF -> 3300uF | 01/01/70 00:00 | |
| re:noise | 01/01/70 00:00 | |
| Exactly the same | 01/01/70 00:00 | |
| test of signal | 01/01/70 00:00 | |
| It's over 1.2m | 01/01/70 00:00 | |
| TWO bypass caps. | 01/01/70 00:00 | |
| Two were found | 01/01/70 00:00 | |
| Usenet | 01/01/70 00:00 | |
| Why using a PLL, when a bandpass can ... | 01/01/70 00:00 | |
| which is why ,,,, | 01/01/70 00:00 | |
| Not sure what you meant.. | 01/01/70 00:00 | |
| Already | 01/01/70 00:00 | |
| But it MUST work properly!! | 01/01/70 00:00 | |
| Circuit here | 01/01/70 00:00 | |
| Op-amp to replace LM324 | 01/01/70 00:00 | |
| Non-inverting Input Voltage Divider | 01/01/70 00:00 | |
| LM567 | 01/01/70 00:00 | |
| re:LM324 | 01/01/70 00:00 | |
| re:wrong link | 01/01/70 00:00 | |
| No AGC | 01/01/70 00:00 | |
| AGC | 01/01/70 00:00 | |
| Yes | 01/01/70 00:00 | |
| re: no AGC | 01/01/70 00:00 | |
| LMC6032 is much more linear than LM324 | 01/01/70 00:00 | |
| re: | 01/01/70 00:00 | |
| re:attenuation of signal | 01/01/70 00:00 | |
| Good ones and bad ones | 01/01/70 00:00 | |
| another article of interest | 01/01/70 00:00 | |
| tramsmit & receive | 01/01/70 00:00 | |
| how to measure the distance perfectly? | 01/01/70 00:00 | |
| Fatal Error! | 01/01/70 00:00 | |
| How about this one.... | 01/01/70 00:00 | |
| Ultrasonic Detection Code! | 01/01/70 00:00 | |
| is that right? | 01/01/70 00:00 | |
| Not right,,,,, | 01/01/70 00:00 | |
| Thanks! | 01/01/70 00:00 | |
| another missing! | 01/01/70 00:00 | |
| i'll try it.. | 01/01/70 00:00 | |
| Some Applications of ultrasonic | 01/01/70 00:00 | |
| "Op amps for everyone" | 01/01/70 00:00 | |
| woo... tiring trip | 01/01/70 00:00 | |
| Check this one | 01/01/70 00:00 | |
| Thanks | 01/01/70 00:00 | |
| is it not fundamentally wrong | 01/01/70 00:00 | |
| Both | 01/01/70 00:00 | |
| I knew that... | 01/01/70 00:00 | |
| Synthetic grounds | 01/01/70 00:00 | |
| no, Kai | 01/01/70 00:00 | |
| Steve, Erik | 01/01/70 00:00 | |
| The circuit works, but... | 01/01/70 00:00 | |
| Moral | 01/01/70 00:00 | |
| Puh, what antennas... | 01/01/70 00:00 | |
| Which means I can't use breadboard | 01/01/70 00:00 | |
| In one word. | 01/01/70 00:00 | |
| Using the LM318 | 01/01/70 00:00 | |
| Missing 10K | 01/01/70 00:00 | |
| More caps | 01/01/70 00:00 | |
| Where? | 01/01/70 00:00 | |
| Parallel | 01/01/70 00:00 | |
| Does it work now? | 01/01/70 00:00 | |
| Yes, it works fine | 01/01/70 00:00 | |
| Theoretical work missed | 01/01/70 00:00 | |
| Fatal Error! | 01/01/70 00:00 | |
| Another article to peruse | 01/01/70 00:00 | |
| Another one... | 01/01/70 00:00 | |
| same application | 01/01/70 00:00 | |
| Sorry | 01/01/70 00:00 | |
| Why sorry? | 01/01/70 00:00 | |
| That's exactly what I want to do | 01/01/70 00:00 | |
| which one is the best way? | 01/01/70 00:00 | |
| Capacitors | 01/01/70 00:00 | |
| i've got it | 01/01/70 00:00 | |
| not the best solution | 01/01/70 00:00 | |
| Laser ranging | 01/01/70 00:00 | |
| how much | 01/01/70 00:00 | |
| I've withdrawn from the competition | 01/01/70 00:00 | |
| NOT finance | 01/01/70 00:00 | |
| Re: money is not everything | 01/01/70 00:00 | |
| Good Luck | 01/01/70 00:00 | |
| good luck | 01/01/70 00:00 | |
| Good luck | 01/01/70 00:00 | |
| Thanks! | 01/01/70 00:00 | |
| The noise again | 01/01/70 00:00 | |
| re:link | 01/01/70 00:00 | |
| Link | 01/01/70 00:00 | |
| this is the link | 01/01/70 00:00 | |
| re:noise | 01/01/70 00:00 | |
| 5-14 Khz | 01/01/70 00:00 | |
| re:5-14kHz | 01/01/70 00:00 | |
| The Noise Amplitude | 01/01/70 00:00 | |
| gain | 01/01/70 00:00 | |
| the problem is gain | 01/01/70 00:00 | |
| Schematic | 01/01/70 00:00 | |
| Thank You but... | 01/01/70 00:00 | |
| Thank You but... | 01/01/70 00:00 | |
| 1/4Watt is enough | 01/01/70 00:00 | |
| Simulation result | 01/01/70 00:00 | |
| Strange plots... | 01/01/70 00:00 | |
| How about Compensation? | 01/01/70 00:00 | |
| Not needed | 01/01/70 00:00 | |
| Bigger Pulse | 01/01/70 00:00 | |
| Bridge configuration can help | 01/01/70 00:00 | |
| The same circuit but... | 01/01/70 00:00 | |
| ...but much stronger | 01/01/70 00:00 | |
| I have tried | 01/01/70 00:00 | |
| What do you mean by ripple? | 01/01/70 00:00 | |
| The ripple | 01/01/70 00:00 | |
| No, it is not. The output from a logic | 01/01/70 00:00 | |
| Answer | 01/01/70 00:00 | |
| Yup Kai | 01/01/70 00:00 | |
| It's to adjust oscillating frequency | 01/01/70 00:00 | |
Finished | 01/01/70 00:00 | |
| Exams VS academic | 01/01/70 00:00 | |
| "Plan B" | 01/01/70 00:00 | |
| Universities in HongKong | 01/01/70 00:00 |