A
aerelD
- Jan 1, 1970
- 0
I am in need of some help as I attempt to improve my circuit design
skills. I am trying to reverse engineer one of those aroma dispensers
that use the little piezo-electric atomizers and a bottle of smelly
oil. I have measured and characterized the signal at all the nodes on
that circuit.
The trouble is they put that lame potted bare silicon die on the board
so you have no idea what it's doing. I want to put on a little
microcontroller or something and drive the atomizer for myself. The
signal going into the power mosfet part is essentially a 3V square
wave with maybe a 35% duty cycle. It comes out of the mosfet into a
little transformer (which I am not understanding it's connections, but
that may be another discussion), a big 3300uF cap and a 220uH inductor
before going out to the atomizer.
There is a cap, a diode and another inductor but they all seem to be
on the input side of the silicon part - possibly just for timing and
blocking?
Anyway, if any of you kind and smart folks out there (does sucking up
work in this group?) have any pointers for me I would very much
appreciate it. It seems fairly simple, but I'm not able to completely
recreate the final output signal. I have a function generator but I
can't figure out how, or if it's possible, to set the duty cycle to
something other than 50%. When I drive my circuit with the closest
signal I can get, it doesn't get anywhere near the 150V (220v pk to
pk) needed for the atomizer.
Many thanks in advance.
skills. I am trying to reverse engineer one of those aroma dispensers
that use the little piezo-electric atomizers and a bottle of smelly
oil. I have measured and characterized the signal at all the nodes on
that circuit.
The trouble is they put that lame potted bare silicon die on the board
so you have no idea what it's doing. I want to put on a little
microcontroller or something and drive the atomizer for myself. The
signal going into the power mosfet part is essentially a 3V square
wave with maybe a 35% duty cycle. It comes out of the mosfet into a
little transformer (which I am not understanding it's connections, but
that may be another discussion), a big 3300uF cap and a 220uH inductor
before going out to the atomizer.
There is a cap, a diode and another inductor but they all seem to be
on the input side of the silicon part - possibly just for timing and
blocking?
Anyway, if any of you kind and smart folks out there (does sucking up
work in this group?) have any pointers for me I would very much
appreciate it. It seems fairly simple, but I'm not able to completely
recreate the final output signal. I have a function generator but I
can't figure out how, or if it's possible, to set the duty cycle to
something other than 50%. When I drive my circuit with the closest
signal I can get, it doesn't get anywhere near the 150V (220v pk to
pk) needed for the atomizer.
Many thanks in advance.