Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Is this a bridge RECTIFIER?

Status
Not open for further replies.

g_ko241988

Newbie level 3
Joined
Oct 12, 2009
Messages
4
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Location
Philippines
Activity points
1,310
Is there anyone that could identify this circuitry?
and can you give an oscilloscope output (in picture) if possible in details of what you notice about this circuit..actually I'm only a student..And doing an experiment for this device...but then there a lack of facilities/ equipment here in our school...like oscilloscope.. so, i could not perform very well about this..
 

snafflekid

Full Member level 4
Joined
May 9, 2007
Messages
214
Helped
31
Reputation
62
Reaction score
8
Trophy points
1,298
Location
USA
Activity points
2,644
AB will be twice the peak voltage of the input. For positive voltage, the top diode will conduct, for negative voltage the left diode will conduct. The right and bottom diodes do nothing. Maybe the connections can be reconfigured for different input voltages.
 

g_ko241988

Newbie level 3
Joined
Oct 12, 2009
Messages
4
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Location
Philippines
Activity points
1,310
Is this circuit consider or performing as voltage multiplier or doubler or tripler..? cause actually i'm wondering for that kind of circuit.....
then the circuit is fixed already..
In your observation, is the output of the circuit is an AC power or DC?
 

hkBattousai

Advanced Member level 4
Joined
Jun 16, 2007
Messages
118
Helped
5
Reputation
10
Reaction score
1
Trophy points
1,298
Location
Turkey
Activity points
2,182
This circuit is nothing but a modified bridge rectifier. It doesn't triple or double the input voltage. Actually this circuit is a "good" bridge rectifier. Diodes are connected parallel to the capacitors in a smart way, so that it is guarantied that the voltage level on the capacitors will always be higher than zero.

You can use this kind of rectifier for rectifying very low voltages (to prevent high noise to create negative peaks), or for circuits which can easily break down at negative supply voltages.
 

g_ko241988

Newbie level 3
Joined
Oct 12, 2009
Messages
4
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Location
Philippines
Activity points
1,310
is there anyone happen to see that circuitry above?in web or in a book..
coz' actually i'm not totally convince.....
i need more evidence..and explanation possible...
coz there conflict happening here..i dont know which one is true...
 

rajudp

Advanced Member level 2
Joined
May 27, 2006
Messages
644
Helped
123
Reputation
246
Reaction score
96
Trophy points
1,308
Location
India
Activity points
4,055
this is a voltage doubler circuit, normally used to for fused tube lights. with 230v input. connect a 60w bulb or choke series with the circuit
 

g_ko241988

Newbie level 3
Joined
Oct 12, 2009
Messages
4
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Location
Philippines
Activity points
1,310
caN you give me a website that can explain maybe about thjs matter....actually i found it out that is really a voltage doupler but then there is something much more unique characteristics of this that i observe which is i cant explain how it goes...because of lack of equipment for testing.. so, then if you can help me or give an explaination how it works then much better..thanks a lot..in advance
 

praveensss

Junior Member level 2
Joined
Dec 31, 2009
Messages
24
Helped
2
Reputation
4
Reaction score
1
Trophy points
1,283
Location
Bangalore
Activity points
1,401
Here is how I look at it:
The output across the top capacitor would be 78*1.141 = 110V.
The path (+ve) is top diode, top capacitor and back to supply.

The output across the bottom capacitor would be 78*1.141 = 110V.
The path (-ve) is left diode, bottom capacitor and back to supply.

Hence the total voltage is 2*110=220V DC, a Voltage doubler, half wave rectification.

So what do the other 2 diodes do? Let us look at the load path.
The top capacitor discharges through the load (here a voltmeter) and bottom diode.
The bottom capacitor powers the load through the right diode!
 

praveensss

Junior Member level 2
Joined
Dec 31, 2009
Messages
24
Helped
2
Reputation
4
Reaction score
1
Trophy points
1,283
Location
Bangalore
Activity points
1,401
Ok, To make it a little more clearer,
The top capacitor gets charged during the +ve half cycle by the top diode. At this time, the bottom capacitor provides the current to the load via the diode across the top capacitor, thus providing the load with a constant current without ripple.

It would have been better to redraw the circuit as a full wave rectifier with the dioddes in parallel with the caps.
 

Status
Not open for further replies.
Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top