File: /var/www/html/simulink/circuit/e-555pulsemod.html
<meta name="viewport" content="width=640">
<title>555 Pulse Width Modulator</title>
<link rel="SHORTCUT ICON" href="favicon.ico">
<body>
<hr>
<table><tr><td>
<iframe width=640 height=500 src="circuitjs.html?startCircuit=555pulsemod.txt"></iframe>
</td><td width="20"> </td><td valign="top">
</td>
</tr></table>
<p>
This circuit encodes a voltage with
<a
href="http://en.wikipedia.org/wiki/Pulse-width_modulation">pulse-width
modulation</a> using a
<a href="http://en.wikipedia.org/wiki/555_timer_IC">555 timer
chip</a>. The width of the output pulses varies depending on
a control voltage.
<p>
The width of the pulses is set by a <a href="http://en.wikipedia.org/wiki/Triangle_wave">triangle wave</a> oscillator connected
to the "ctl" input of the 555. The rest of the circuit is just like
the <a href="e-555square.html">square wave oscillator</a>. By
applying a voltage to the "ctl" input (normally 2/3 V<sub>in</sub>),
we can control the voltage
which ends a timing interval. When the "th" input reaches this
value, the output goes low. So the 555 will oscillate faster when the
ctl input is lower.
<p>
Next: <a href="e-555schmitt.html">555 Schmitt Trigger (inverting)</a><p>
Previous: <a href="e-555sequencer.html">555 Pulse Sequencer</a><p>
<a href="e-index.html#555pulsemod">Index</a><p>
<a href="index.html">Simulator Home</a>
<hr>
<script type="text/javascript"><!--
google_ad_client = "pub-1974179407250396";
/* 728x90, created 7/9/08 */
google_ad_slot = "3265434789";
google_ad_width = 728;
google_ad_height = 90;
//-->
</script>
<script type="text/javascript"
src="http://pagead2.googlesyndication.com/pagead/show_ads.js">
</script>
<hr>
<a href="http://www.falstad.com/mathphysics.html"><img src="/mathphysics_small.gif"></a>
<a href="http://www.falstad.com/index.html"><img src="/me_small.gif"></a>
<br><i>java@</i><i>falstad.com</i>
<br>Generated Wed Dec 7 2016
</body>