Comments on: DrawDio http://retrointerfacing.com/?p=100 - connecting past and future - Mon, 06 Sep 2010 11:26:08 +0000 http://wordpress.org/?v=2.7 hourly 1 By: edwin http://retrointerfacing.com/?p=100&cpage=1#comment-411 edwin Mon, 22 Dec 2008 11:39:44 +0000 http://retrointerfacing.com/?p=100#comment-411 No, in fact I did not change values for resistors and capacitors. Oh.. I had no 300K resistor lying around, since 330K is more common (e12? range), but that does not make a lot of difference since skin+pencil resistance can change so much. It only sets the upper limit (highest pitch). The transistors I've used were BC547 and BC557, since they are more common in Europe (and happened to be lying around). The speaker is quite large. I first tried the system with a piezo buzzer (from a happy-birthday-card) which also can be used without the transistor amp. It doesn't make as much noise as the final used speaker (which was very nice and flat as you can see in the pictures) The major difference is the power supply, since a 555 theoretically needs at least 5V (according to spec). I tried, and found it to be working quite well down to 3V.. So I used a 3.6V lithium battery, salvaged from a shakelight. I haven't tested the durability, but it can be recharged in matter of seconds, and will be running for evenings at a row No, in fact I did not change values for resistors and capacitors. Oh.. I had no 300K resistor lying around, since 330K is more common (e12? range), but that does not make a lot of difference since skin+pencil resistance can change so much. It only sets the upper limit (highest pitch). The transistors I’ve used were BC547 and BC557, since they are more common in Europe (and happened to be lying around). The speaker is quite large. I first tried the system with a piezo buzzer (from a happy-birthday-card) which also can be used without the transistor amp. It doesn’t make as much noise as the final used speaker (which was very nice and flat as you can see in the pictures)

The major difference is the power supply, since a 555 theoretically needs at least 5V (according to spec). I tried, and found it to be working quite well down to 3V.. So I used a 3.6V lithium battery, salvaged from a shakelight. I haven’t tested the durability, but it can be recharged in matter of seconds, and will be running for evenings at a row

]]> By: Marko http://retrointerfacing.com/?p=100&cpage=1#comment-359 Marko Fri, 19 Dec 2008 13:34:31 +0000 http://retrointerfacing.com/?p=100#comment-359 Did you change any other components as well (resistors, capacitors) to make it work with a 555? I too am interested in making this, but can't get my hands on a 551. Did you change any other components as well (resistors, capacitors) to make it work with a 555? I too am interested in making this, but can’t get my hands on a 551.

]]> By: Olechka-persik http://retrointerfacing.com/?p=100&cpage=1#comment-36 Olechka-persik Tue, 09 Dec 2008 04:53:32 +0000 http://retrointerfacing.com/?p=100#comment-36 Огромное спасибо за потрясающие идеи!!! Буду следить за блогом, много всего интересного. А мой блог о науке, надеюсь, тоже понравится ;) (translation according to babelfish) Enormous thanks for the staggering ideas!!! I will follow [blogom], there is much entire interesting. But my [blog] about the science, I hope, also it will be pleased;) Огромное спасибо за потрясающие идеи!!! Буду следить за блогом, много всего интересного. А мой блог о науке, надеюсь, тоже понравится ;)

(translation according to babelfish) Enormous thanks for the staggering ideas!!! I will follow [blogom], there is much entire interesting. But my [blog] about the science, I hope, also it will be pleased;)

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