Wire recorders
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cormacwmccreary
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Wire recorders
Hi! I'm following a guide to making a wire recorder on this website (https://www.sciencebuddies.org/science- ... -on-a-wire). I was wondering how powerful the electromagnet has to be to record to the steel wire? I'm using a larger ferrite core that I salvaged from a dead power supply. I currently have 400 turns on the core. I can hold the core up to a spinning magnet to get a signal to an amp, ( sound like a sine wave). anyways if anyone can say how powerful the magnet has to bee that would be great!
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norman40
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Re: Wire recorders
Hi cormacwmccreary,
The project procedure indicates that 200 to 300 wire turns on the core should be enough to produce a signal for recording. But you may need more turns if your ferrite core is much larger than the one specified in the project material list.
From the information you provided it seems that your electromagnet is working in your test playback experiment. If you are not able to record you might try increasing the amplifier volume to the record head. And you might try different types of recording wire as suggested in the project procedure.
I hope this helps. Please post again if you have more questions.
A. Norman
The project procedure indicates that 200 to 300 wire turns on the core should be enough to produce a signal for recording. But you may need more turns if your ferrite core is much larger than the one specified in the project material list.
From the information you provided it seems that your electromagnet is working in your test playback experiment. If you are not able to record you might try increasing the amplifier volume to the record head. And you might try different types of recording wire as suggested in the project procedure.
I hope this helps. Please post again if you have more questions.
A. Norman
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cormacwmccreary
- Posts: 7
- Joined: Tue Aug 20, 2019 11:49 am
- Occupation: Student
Re: Wire recorders
Hi! thanks for the reply! a lot has happened since then. I was able to use the amp and record/playback head to play over tape recorder head (kind of like those head to head cassette cartridges). I was also able to get my hands on some webster Chicago recording wire (yay). still can't record with the head to the wire through, I even changed the number of windings from 400 to 500. don't know whats going on here. tried to get a video of the inside of a webster Chicago record/playback head, no dice. I at least know that the head is working, because when I put a magnet on the ferrite core with the windings it makes a noise that sounds like someone knocking on a door. Any help is appreciated! I'm all ears!
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norman40
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Re: Wire recorders
Hi cormacwmccreary,
I'm assuming that increasing the signal amplification to your recording head did not produce a recording on the wire. Is the wire contacting the ferrite core during when you try to record? And you might experiment with the wire speed during recording.
It's possible that the salvaged ferrite core you're using is too large or otherwise inappropriate for use in this application. You might want to try using the type of ferrite beads specified in the project materials list instead.
Some previous forum discussions of this topic may be of interest to you :
viewtopic.php?t=3834
viewtopic.php?t=5039
viewtopic.php?t=5614
I hope this helps. Please post again if you have more questions.
A. Norman
I'm assuming that increasing the signal amplification to your recording head did not produce a recording on the wire. Is the wire contacting the ferrite core during when you try to record? And you might experiment with the wire speed during recording.
It's possible that the salvaged ferrite core you're using is too large or otherwise inappropriate for use in this application. You might want to try using the type of ferrite beads specified in the project materials list instead.
Some previous forum discussions of this topic may be of interest to you :
viewtopic.php?t=3834
viewtopic.php?t=5039
viewtopic.php?t=5614
I hope this helps. Please post again if you have more questions.
A. Norman
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cormacwmccreary
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- Joined: Tue Aug 20, 2019 11:49 am
- Occupation: Student
Re: Wire recorders
Hi! thanks for the quick reply! I switched the core I was using to one 11mm in size. after winding the wire around the core 300 times I still can't get a signal. if it helps im using a 5-volt amp running over USB power that I bought online. is that enough voltage? any answer can help!
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norman40
- Former Expert
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- Joined: Mon Jul 14, 2014 1:49 pm
- Occupation: retired chemist
- Project Question: Volunteer
- Project Due Date: n/a
- Project Status: Not applicable
Re: Wire recorders
Hi cormacwmccreary,
Does your amplifier have an input for an audio source and an output that can power a speaker?
If so, the amplifier is probably OK for your project.
What are you using for an audio source when you try to record? The project procedure suggests either a microphone or an audio player (CD or other). Are you sure that your audio source emits a signal? And are your sure that you have good connections from the audio source to the amp, and from the amp to the recording head? You might try connecting your multimeter to the amp output and recording head to verify that you have a signal there. See the section of the project procedure titled “Experiments”.
I hope this helps. Please post again if you have more questions.
A. Norman
Does your amplifier have an input for an audio source and an output that can power a speaker?
If so, the amplifier is probably OK for your project.
What are you using for an audio source when you try to record? The project procedure suggests either a microphone or an audio player (CD or other). Are you sure that your audio source emits a signal? And are your sure that you have good connections from the audio source to the amp, and from the amp to the recording head? You might try connecting your multimeter to the amp output and recording head to verify that you have a signal there. See the section of the project procedure titled “Experiments”.
I hope this helps. Please post again if you have more questions.
A. Norman
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cormacwmccreary
- Posts: 7
- Joined: Tue Aug 20, 2019 11:49 am
- Occupation: Student
Re: Wire recorders
Hi! thanks for a quick reply!
yes, It does have an input and output on the amp capable of powering a speaker. as for the audio source, I'm using my phone with a jack plugged into the mic input and the read/write head connected to the headphone output (its the only output it has). I can confirm that all the connections are good since when I put the read/write head next to a tape recorder head, the music will play through the tape recorder. I also know that the read function of the read/write head works since when I hook the head up to the mic input and the speaker to the headphone output and put a magnet up to the head I can hear the cracking on the speakers I mentioned before. I just can't record to the wire is the problem, also when hook my multimeter up to the head, I don't get a significant reading on AC or DC, I also switched out my old larger ferrite core for a much smaller one, about 11m in size.
Any help is appreciated!
yes, It does have an input and output on the amp capable of powering a speaker. as for the audio source, I'm using my phone with a jack plugged into the mic input and the read/write head connected to the headphone output (its the only output it has). I can confirm that all the connections are good since when I put the read/write head next to a tape recorder head, the music will play through the tape recorder. I also know that the read function of the read/write head works since when I hook the head up to the mic input and the speaker to the headphone output and put a magnet up to the head I can hear the cracking on the speakers I mentioned before. I just can't record to the wire is the problem, also when hook my multimeter up to the head, I don't get a significant reading on AC or DC, I also switched out my old larger ferrite core for a much smaller one, about 11m in size.
Any help is appreciated!
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norman40
- Former Expert
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- Joined: Mon Jul 14, 2014 1:49 pm
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Re: Wire recorders
Hi cormacwmccreary,
Based on your description it seems that you've done a great job with testing the read/write head and the associated connections. And it appears that you are getting a signal through the read/write head.
It's possible that you are recording on the wire with your setup but the signal is just too faint to hear. So you might try boosting the signal to the head during the recording. To do this you can try increasing the volume on your phone in addition to increasing the audio amplifier volume. You may need to increase the volume during playback as well. Also, the recording level on the wire should increase if you have a smaller gap in the ferrite core and if the wire is in contact with the core during recording.
I hope this helps. Please post again if you have more questions.
A. Norman
Based on your description it seems that you've done a great job with testing the read/write head and the associated connections. And it appears that you are getting a signal through the read/write head.
It's possible that you are recording on the wire with your setup but the signal is just too faint to hear. So you might try boosting the signal to the head during the recording. To do this you can try increasing the volume on your phone in addition to increasing the audio amplifier volume. You may need to increase the volume during playback as well. Also, the recording level on the wire should increase if you have a smaller gap in the ferrite core and if the wire is in contact with the core during recording.
I hope this helps. Please post again if you have more questions.
A. Norman
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cormacwmccreary
- Posts: 7
- Joined: Tue Aug 20, 2019 11:49 am
- Occupation: Student
Re: Wire recorders
HI! thanks for the quick reply!
So, I might have figured out what is wrong with my wire recorder. the amp I was using, was not an amp. instead it was a USB external sound card. it was in fact not amplifying the sound at all! thats why I got nothing out of the headphone output! I ordered a small 12v 1amp amplifier on amazon and it should be arriving today. in other news, I got the mechanics for the wire delivery spool working. I'll give an update on how it goes! stay tuned!
So, I might have figured out what is wrong with my wire recorder. the amp I was using, was not an amp. instead it was a USB external sound card. it was in fact not amplifying the sound at all! thats why I got nothing out of the headphone output! I ordered a small 12v 1amp amplifier on amazon and it should be arriving today. in other news, I got the mechanics for the wire delivery spool working. I'll give an update on how it goes! stay tuned!
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cormacwmccreary
- Posts: 7
- Joined: Tue Aug 20, 2019 11:49 am
- Occupation: Student
Re: Wire recorders
Hi! I'm back!
still no luck... I used a cheap amp called "PAM8610" I got off of amazon. ive connected the read/write head to the amp output and played music over the jack, then I plugged the head into the jack and...nothing. I get static over the speaker and nothing else. the amp works since I can play music over the speaker. any help would be appreciated!
still no luck... I used a cheap amp called "PAM8610" I got off of amazon. ive connected the read/write head to the amp output and played music over the jack, then I plugged the head into the jack and...nothing. I get static over the speaker and nothing else. the amp works since I can play music over the speaker. any help would be appreciated!
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norman40
- Former Expert
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- Joined: Mon Jul 14, 2014 1:49 pm
- Occupation: retired chemist
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- Project Status: Not applicable
Re: Wire recorders
Hi cormacwmccreary,
After reviewing all of our posts, I want to make sure we're “on the same page”. So I'm suggesting that you follow the steps outlined below.
I took a look at the PAM8610 amplifiers on Amazon and there are several versions. Did you get one with an input jack for a 1/8 inch plug, speaker terminals and a volume control?
If so you should connect your phone headphone output to the amp input jack. Connect the wires from the record head to one of the pairs of amp speaker terminals. Try recording with the amp volume knob set about midway between maximum and minimum and with the volume control on your phone set at about midway. Make sure to move the wire steadily over the gap in the ferrite core with the wire in contact with the core.
To playback, connect the wires from the head to the amp input jack. Leave the amp volume control set at about midway. Connect a speaker to the one of the pairs of amp speaker terminals. Now move the wire steadily over the gap in the ferrite core while making sure the wire contacts the core. Hopefully you'll hear something besides static. If you don't hear anything, try playback at a higher amp volume or try recording again with a higher amp volume.
I hope this helps. Please post again if you have more questions.
A. Norman
After reviewing all of our posts, I want to make sure we're “on the same page”. So I'm suggesting that you follow the steps outlined below.
I took a look at the PAM8610 amplifiers on Amazon and there are several versions. Did you get one with an input jack for a 1/8 inch plug, speaker terminals and a volume control?
If so you should connect your phone headphone output to the amp input jack. Connect the wires from the record head to one of the pairs of amp speaker terminals. Try recording with the amp volume knob set about midway between maximum and minimum and with the volume control on your phone set at about midway. Make sure to move the wire steadily over the gap in the ferrite core with the wire in contact with the core.
To playback, connect the wires from the head to the amp input jack. Leave the amp volume control set at about midway. Connect a speaker to the one of the pairs of amp speaker terminals. Now move the wire steadily over the gap in the ferrite core while making sure the wire contacts the core. Hopefully you'll hear something besides static. If you don't hear anything, try playback at a higher amp volume or try recording again with a higher amp volume.
I hope this helps. Please post again if you have more questions.
A. Norman
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cormacwmccreary
- Posts: 7
- Joined: Tue Aug 20, 2019 11:49 am
- Occupation: Student
Re: Wire recorders
Hi!
after doing some calculating ive determined that my read/write head is outputting 8.57 teslas (magnetic field). is this the correct amount for the wire recorder, if not does it need to be higher or lower? I'm all ears!
(.25 amps, 7mm in length, 300 turns, and the permeability of ferrite is 8.0 times 10 to the power of -4)
after doing some calculating ive determined that my read/write head is outputting 8.57 teslas (magnetic field). is this the correct amount for the wire recorder, if not does it need to be higher or lower? I'm all ears!
(.25 amps, 7mm in length, 300 turns, and the permeability of ferrite is 8.0 times 10 to the power of -4)
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norman40
- Former Expert
- Posts: 1022
- Joined: Mon Jul 14, 2014 1:49 pm
- Occupation: retired chemist
- Project Question: Volunteer
- Project Due Date: n/a
- Project Status: Not applicable
Re: Wire recorders
Hi cormacwmccreary,
I don't know the “correct” magnetic field level for the wire recorder. I suspect that the required field strength depends on the wire characteristics and probably several other factors. You might note that the permeability depends on the ferrite composition and can vary by a factor of 100. So the composition of your ferrite core is an important determinant of the field strength.
That said, my suggestion is to try the steps outlined in my previous post. These steps are aimed at systematically varying amplification during recording and playback. If you don't have any success with this you might try the type of ferrite core specified in the project procedure.
I hope this helps. Please post again if you have more questions.
A. Norman
I don't know the “correct” magnetic field level for the wire recorder. I suspect that the required field strength depends on the wire characteristics and probably several other factors. You might note that the permeability depends on the ferrite composition and can vary by a factor of 100. So the composition of your ferrite core is an important determinant of the field strength.
That said, my suggestion is to try the steps outlined in my previous post. These steps are aimed at systematically varying amplification during recording and playback. If you don't have any success with this you might try the type of ferrite core specified in the project procedure.
I hope this helps. Please post again if you have more questions.
A. Norman