555 - Revision history

Adamcolton at 19:13, 2 March 2018

2018-03-02T19:13:26Z

← Older revision		Revision as of 19:13, 2 March 2018
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	I don't completely understand Control, it's intended to be used to set, but can we read a voltage there too? Can the control voltage be higher than V+ (to use the 555 to step down an output)?		I don't completely understand Control, it's intended to be used to set, but can we read a voltage there too? Can the control voltage be higher than V+ (to use the 555 to step down an output)?

			== PWM ==
			The basic a-stable mode can only do PWM above 50% duty cycle. That can be reduced with a diode across R2, I need to experiment with that.

			For a more accurate PWM a 556 can be used with the first half in a-stable mode for the frequency and the second half in mono-stable mode to set the pulse per cycle length. A large part of what I want this for is a MOSFET driver, I'm curious if I could integrate a charge pump into the first stage.

	[[Category:Electronics]]		[[Category:Electronics]]
	[[Category:Notes]]		[[Category:Notes]]

Adamcolton at 18:10, 2 March 2018

2018-03-02T18:10:09Z

← Older revision		Revision as of 18:10, 2 March 2018
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	When the output is low, the discharge has a low impedance connection to ground.		When the output is low, the discharge has a low impedance connection to ground.

	Besides the basic modes (monostable, bistable and astable) it can be used for digital logic. The piece that turned me on to this was using it as a temperature controller. Where the 1/3 level corresponds to "turn on the heater" and the 2/3 level corresponds to "turn off the heater". Any logic of that nature.		Besides the basic modes (monostable, bistable and astable) it can be used for digital logic. The piece that turned me on to this was using it as a temperature controller. Where the 1/3 level corresponds to "turn on the heater" and the 2/3 level corresponds to "turn off the heater". Any logic of that nature. But that involves some tricky resistor math to convert the voltage being received to the desired voltage.

	If a signal is fed into Control Voltage with the circuit in monostable mode, it becomes a class D amp. I'll put this note here, this took me a while to understand; the out put of a PWM encoder, to convert back to analog, needs to go through a resistor and a diode, and there needs to be a cap in parallel with the load.		If a signal is fed into Control Voltage with the circuit in monostable mode, it becomes a class D amp. I'll put this note here, this took me a while to understand; the out put of a PWM encoder, to convert back to analog, needs to go through a resistor and a diode, and there needs to be a cap in parallel with the load.

Adamcolton at 01:23, 3 February 2018

2018-02-03T01:23:42Z

← Older revision		Revision as of 01:23, 3 February 2018
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			* 200mA
			* max frequency 500kHz - 2MHz

	== Pins ==		== Pins ==

Adamcolton: /* States */

2017-02-20T16:00:24Z

States

← Older revision		Revision as of 16:00, 20 February 2017
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	If the Threshold is Low and the Trigger is High, the Output is High.		If the Threshold is Low and the Trigger is High, the Output is High.

	If ~~the Trigger is Low and the Threshold is High~~, the ~~Output remains in~~ it's previous state.		If both are low, the output keeps it's previous state.

			NOTE: I think I need to test this again in ternary.

	== Questions ==		== Questions ==

Adamcolton at 03:28, 16 February 2017

2017-02-16T03:28:00Z

← Older revision		Revision as of 03:28, 16 February 2017
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	On the one I tested, there was a small voltage drop at the output.		On the one I tested, there was a small voltage drop at the output.

			I need more testing, but it seems like changing the ctrl by too much just doesn't work. I tried setting it above Vcc and nothing really worked.

	== States ==		== States ==

Adamcolton at 03:04, 16 February 2017

2017-02-16T03:04:46Z

← Older revision		Revision as of 03:04, 16 February 2017
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	If a signal is fed into Control Voltage with the circuit in monostable mode, it becomes a class D amp. I'll put this note here, this took me a while to understand; the out put of a PWM encoder, to convert back to analog, needs to go through a resistor and a diode, and there needs to be a cap in parallel with the load.		If a signal is fed into Control Voltage with the circuit in monostable mode, it becomes a class D amp. I'll put this note here, this took me a while to understand; the out put of a PWM encoder, to convert back to analog, needs to go through a resistor and a diode, and there needs to be a cap in parallel with the load.

			On the one I tested, there was a small voltage drop at the output.

	== States ==		== States ==

Adamcolton at 03:01, 16 February 2017

2017-02-16T03:01:40Z

← Older revision		Revision as of 03:01, 16 February 2017
Line 21:		Line 21:

	If a signal is fed into Control Voltage with the circuit in monostable mode, it becomes a class D amp. I'll put this note here, this took me a while to understand; the out put of a PWM encoder, to convert back to analog, needs to go through a resistor and a diode, and there needs to be a cap in parallel with the load.		If a signal is fed into Control Voltage with the circuit in monostable mode, it becomes a class D amp. I'll put this note here, this took me a while to understand; the out put of a PWM encoder, to convert back to analog, needs to go through a resistor and a diode, and there needs to be a cap in parallel with the load.

			== States ==
			If the Threshold is High, the Output is always Low.

			If the Threshold is Low and the Trigger is High, the Output is High.

			If the Trigger is Low and the Threshold is High, the Output remains in it's previous state.

	== Questions ==		== Questions ==

Adamcolton at 17:23, 15 February 2017

2017-02-15T17:23:51Z

← Older revision		Revision as of 17:23, 15 February 2017
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	The control voltage can set the 2/3 level directly. Often it is not used and connected to ground with 10uF cap.		The control voltage can set the 2/3 level directly. Often it is not used and connected to ground with 10uF cap.

	~~The discharge is a bit confusing. It tied to the collector of a transistor internally. The emitter is tied to the output. So when~~ the output is ~~high~~, discharge ~~is connected to ground, when output is~~ low~~, there is high resistance~~ to ground.		When the output is low, the discharge has a low impedance connection to ground.

	Besides the basic modes (monostable, bistable and astable) it can be used for digital logic. The piece that turned me on to this was using it as a temperature controller. Where the 1/3 level corresponds to "turn on the heater" and the 2/3 level corresponds to "turn off the heater". Any logic of that nature.		Besides the basic modes (monostable, bistable and astable) it can be used for digital logic. The piece that turned me on to this was using it as a temperature controller. Where the 1/3 level corresponds to "turn on the heater" and the 2/3 level corresponds to "turn off the heater". Any logic of that nature.
Line 25:		Line 25:

	If BOTH trigger is low and threshold is high, which take precedent? Based on the [https://en.wikipedia.org/wiki/555_timer_IC#Bistable bistable] configuration, I believe that threshold takes precedent.		If BOTH trigger is low and threshold is high, which take precedent? Based on the [https://en.wikipedia.org/wiki/555_timer_IC#Bistable bistable] configuration, I believe that threshold takes precedent.

	~~I think that with a pullup resistor, Discharge would behave as !Output.~~

	I don't completely understand Control, it's intended to be used to set, but can we read a voltage there too? Can the control voltage be higher than V+ (to use the 555 to step down an output)?		I don't completely understand Control, it's intended to be used to set, but can we read a voltage there too? Can the control voltage be higher than V+ (to use the 555 to step down an output)?

Adamcolton at 17:17, 15 February 2017

2017-02-15T17:17:45Z

← Older revision		Revision as of 17:17, 15 February 2017
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	~~I've been reading up a bit on the 555 and I'm beginning to see it's brilliance.~~

	Pins		== Pins ==
	# Ground		# Ground
	# Trigger		# Trigger
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	If a signal is fed into Control Voltage with the circuit in monostable mode, it becomes a class D amp. I'll put this note here, this took me a while to understand; the out put of a PWM encoder, to convert back to analog, needs to go through a resistor and a diode, and there needs to be a cap in parallel with the load.		If a signal is fed into Control Voltage with the circuit in monostable mode, it becomes a class D amp. I'll put this note here, this took me a while to understand; the out put of a PWM encoder, to convert back to analog, needs to go through a resistor and a diode, and there needs to be a cap in parallel with the load.

			== Questions ==

			If BOTH trigger is low and threshold is high, which take precedent? Based on the [https://en.wikipedia.org/wiki/555_timer_IC#Bistable bistable] configuration, I believe that threshold takes precedent.

			I think that with a pullup resistor, Discharge would behave as !Output.

			I don't completely understand Control, it's intended to be used to set, but can we read a voltage there too? Can the control voltage be higher than V+ (to use the 555 to step down an output)?

	[[Category:Electronics]]		[[Category:Electronics]]
	[[Category:Notes]]		[[Category:Notes]]

Adamcolton at 06:02, 6 November 2015

2015-11-06T06:02:59Z

← Older revision		Revision as of 06:02, 6 November 2015
Line 21:		Line 21:
	Besides the basic modes (monostable, bistable and astable) it can be used for digital logic. The piece that turned me on to this was using it as a temperature controller. Where the 1/3 level corresponds to "turn on the heater" and the 2/3 level corresponds to "turn off the heater". Any logic of that nature.		Besides the basic modes (monostable, bistable and astable) it can be used for digital logic. The piece that turned me on to this was using it as a temperature controller. Where the 1/3 level corresponds to "turn on the heater" and the 2/3 level corresponds to "turn off the heater". Any logic of that nature.

	If a signal is fed into Control Voltage with the circuit in monostable mode, it becomes a class D amp.		If a signal is fed into Control Voltage with the circuit in monostable mode, it becomes a class D amp. I'll put this note here, this took me a while to understand; the out put of a PWM encoder, to convert back to analog, needs to go through a resistor and a diode, and there needs to be a cap in parallel with the load.

	[[Category:Electronics]]		[[Category:Electronics]]
	[[Category:Notes]]		[[Category:Notes]]