Serial Number Perspective Rectifier Regulator

Function of a Regulator/Rectifier by Dave Aley. This article was written by Dave Aley, posted on the VFR List and he has graciously allowed me to post it here. This post offers some great guidance on the function of a regulator and rectifier, plus a few other points regarding the electrical system of a bike. Serial Number Perspective Rectifier For Motorcycle. Number 12 (December 2016) pp.3981-4701: A SPECIAL SECTION Selected Peer-Reviewed Articles from the 2016. Testing a Regulator/Rectifier. To determine that a regulator/rectifier is working properly, it's necessary to test each of its diodes to see whether they are forward biasing (allowing current flow) and reverse biasing (preventing current flow) correctly. Regulator/rectifier units vary from model to model, and manufacturer to manufacturer.

1. Serial Number Perspective Rectifier Regulator Circuit
2. Serial Number Perspective Rectifier Regulator Chart
3. Serial Number Perspective Rectifier Regulator Kit
4. Regulator Rectifier Motorcycle
5. Serial Number Perspective Rectifier Regulator Replacement
6. Regulator Rectifier Function

Function of a Regulator/Rectifier

by Dave Aley

Item up for sale is a used rectifier regulator off of a 1999 Honda BF90 outboard. Serial number: BBBL-3000180. It comes just as pictured sold as is with no refunds and returns accepted. For Questions or Customer Service Contact Stroud's Marine at (252)751-0415. Identifying motor by serial number - posted in Skandic / Expedition: I recently tried buying new rubber o-rings for the top end of my sled. Its a 95 Skandic 500 but the motor isnt original. The ones that they gave me are obviously too small and Im told there have been changes through the years.The guy I got the motor from told me it was out of an 89. Its been a solid motor for me but now its.

What precisely is the function of the regulator/rectifier? Does it perform two separate functions, as the name implies, or just one?

It does indeed perform two separate functions. The power coming from your alternator is 3-phase AC power. Each of the three wires coming from your alternator carries AC power, but in each wire the phase is different. It is the job of the rectifier part of the reg/rect to convert the power from 3-phase AC to single-phase DC.

The DC power will not necessarily be at the correct voltage to charge the battery. The alternator always tries (for a given engine RPM) to put out the same amount of power. Since power is equal to volts times amps, if the bike is not using much current (battery fully charged, no heavy electrical loads), the voltage will rise. It is the job of the regulator to supply the load so that the voltage is kept within specified limits. It does this by consuming the excess electrical power as heat.

What is the purpose of ground wires? What will be the result if some electrical components aren't properly grounded?

That depends on the component. If your battery is not properly grounded, for example, you will have intermittent periods of time when it is effectively not in the circuit. When this happens the regulator has to bleed off the excess power that would be going into charging the battery, which will make it somewhat hotter.

Other components may work erratically or intermittently if they do not have a good ground. Turn signals, for example, will often behave very strangely if they are not getting a good ground, since the current will flow to ground through other filaments in the bulb rather than through the ground wire as was intended. Many black boxes will simply fail to function if they are not properly grounded.

What causes corrosion of electrical wires?

Copper corrodes relatively easily in the atmosphere. Add in the effects of connecting dissimilar metals in a wet, dirty environment, and you have got an open invitation for corrosion. If you add a bit of battery acid, you will increase the problem significantly since the copper is trying hard to turn to copper sulfate, which is that bluish powder you see on corroded connections.

Does the alternator serve any purpose other than generating electricity? And why, if the motorcycle requires DC current, doesn't it come equipped with a DC generator instead of an alternator?

Good question. AFAIK, an alternator provides its power in a smoother fashion, and it can begin producing power at a lower RPM. I could be completely off-base on this, though. Besides, a DC generator would require brushes that would have to be changed out regularly.

What duties does the battery perform other than providing the needed current to crank the motor during startup?

It sinks the current from the alternator and provides reserve power for running things when the engine is idling.

Dave Aley
1987 VFR700FII

Technical Corner | Main Garage

• Electronic Circuits Tutorial

• Wave Shaping

• Power Supplies

• Electronic Circuits Resources

• Selected Reading

Serial Number Perspective Rectifier Regulator Circuit

The next and the last stage before load, in a power supply system is the Regulator part. Let us now try to understand what a regulator is and what it does.

The part of electronics that deal with the control and conversion of electric power can be termed as Power Electronics. A regulator is an important device when it comes to power electronics as it controls the power output.

Need for a Regulator

For a Power supply to produce a constant output voltage, irrespective of the input voltage variations or the load current variations, there is a need for a voltage regulator.

A voltage regulator is such a device that maintains constant output voltage, instead of any kind of fluctuations in the input voltage being applied or any variations in current, drawn by the load. The following image gives an idea of what a practical regulator looks like.

Types of Regulators

Regulators can be classified into different categories, depending upon their working and type of connection.

Depending upon the type of regulation, the regulators are mainly divided into two types namely, line and load regulators.

• Line Regulator − The regulator which regulates the output voltage to be constant, in spite of input line variations, it is called as Line regulator.

• Load Regulator − The regulator which regulates the output voltage to be constant, in spite of the variations in load at the output, it is called as Load regulator.

Depending upon the type of connection, there are two type of voltage regulators. They are

• Series voltage regulator
• Shunt voltage regulator

The arrangement of them in a circuit will be just as in the following figures.

Let us have a look at other important regulator types.

Zener Voltage Regulator

A Zener voltage regulator is one which uses Zener diode for regulating the output voltage. We have already discussed the details regarding Zener diode in BASIC ELECTRONICS tutorial.

When the Zener diode is operated in the breakdown or Zener region, the voltage across it is substantially constant for a large change of current through it. This characteristic makes Zener diode a good voltage regulator.

The following figure shows an image of a simple Zener regulator.

The applied input voltage $V_i$ when increased beyond the Zener voltage $V_z$, then the Zener diode operates in the breakdown region and maintains constant voltage across the load. The series limiting resistor $R_s$ limits the input current.

Working of Zener Voltage Regulator

The Zener diode maintains the voltage across it constant in spite of load variations and input voltage fluctuations. Hence we can consider 4 cases to understand the working of a Zener voltage regulator.

Case 1 − If the load current $I_L$ increases, then the current through the Zener diode $I_Z$ decreases in order to maintain the current through the series resistor $R_S$ constant. The output voltage Vo depends upon the input voltage Vi and voltage across the series resistor $R_S$.

This is can be written as

$$V_o=V_{in}-IR_{s}$$

Where $I$ is constant. Therefore, $V_o$ also remains constant.

Case 2 − If the load current $I_L$ decreases, then the current through the Zener diode $I_Z$ increases, as the current $I_S$ through RS series resistor remains constant. Though the current $I_Z$ through Zener diode increases it maintains a constant output voltage $V_Z$, which maintains the load voltage constant.

Case 3 − If the input voltage $V_i$ increases, then the current $I_S$ through the series resistor RS increases. This increases the voltage drop across the resistor, i.e. $V_S$ increases. Though the current through Zener diode $I_Z$ increases with this, the voltage across Zener diode $V_Z$ remains constant, keeping the output load voltage constant.

Case 4 − If the input voltage decreases, the current through the series resistor decreases which makes the current through Zener diode $I_Z$ decreases. But the Zener diode maintains output voltage constant due to its property.

Limitations of Zener Voltage Regulator

There are a few limitations for a Zener voltage regulator. They are −

• It is less efficient for heavy load currents.
• The Zener impedance slightly affects the output voltage.

Hence a Zener voltage regulator is considered effective for low voltage applications. Now, let us go through the other types of voltage regulators, which are made using transistors.

Transistor Series Voltage Regulator

This regulator has a transistor in series to the Zener regulator and both in parallel to the load. The transistor works as a variable resistor regulating its collector emitter voltage in order to maintain the output voltage constant. The figure below shows the transistor series voltage regulator.

With the input operating conditions, the current through the base of the transistor changes. This effects the voltage across the base emitter junction of the transistor $V_{BE}$. The output voltage is maintained by the Zener voltage $V_Z$ which is constant. As both of them are maintained equal, any change in the input supply is indicated by the change in emitter base voltage $V_{BE}$.

Hence the output voltage Vo can be understood as

$$V_O=V_Z+V_{BE}$$

Working of Transistor Series Voltage Regulator

The working of a series voltage regulator shall be considered for input and load variations. If the input voltage is increased, the output voltage also increases. But this in turn makes the voltage across the collector base junction $V_{BE}$ to decrease, as the Zener voltage $V_Z$ remains constant. The conduction decreases as the resistance across emitter collector region increases. This further increases the voltage across collector emitter junction VCE thus reducing the output voltage $V_O$. This will be similar when the input voltage decreases.

When the load changes occur, which means if the resistance of the load decreases, increasing the load current $I_L$, the output voltage $V_O$ decreases, increasing the emitter base voltage $V_{BE}$.

With the increase in the emitter base voltage $V_{BE}$ the conduction increases reducing the emitter collector resistance. This in turn increases the input current which compensates the decrease in the load resistance. This will be similar when the load current increases.

Limitations of Transistor Series Voltage Regulator

Transistor Series Voltage Regulators have the following limitations −

• The voltages $V_{BE}$ and $V_Z$ are affected by the rise in temperature.
• No good regulation for high currents is possible.
• Power dissipation is high.
• Power dissipation is high.
• Less efficient.

To minimize these limitations, transistor shunt regulator is used.

Transistor Shunt Voltage Regulator

$$V_o=V_{in}-IR_{s}$$

Where $I$ is constant. Therefore, $V_o$ also remains constant.

Case 2 − If the load current $I_L$ decreases, then the current through the Zener diode $I_Z$ increases, as the current $I_S$ through RS series resistor remains constant. Though the current $I_Z$ through Zener diode increases it maintains a constant output voltage $V_Z$, which maintains the load voltage constant.

Case 3 − If the input voltage $V_i$ increases, then the current $I_S$ through the series resistor RS increases. This increases the voltage drop across the resistor, i.e. $V_S$ increases. Though the current through Zener diode $I_Z$ increases with this, the voltage across Zener diode $V_Z$ remains constant, keeping the output load voltage constant.

Case 4 − If the input voltage decreases, the current through the series resistor decreases which makes the current through Zener diode $I_Z$ decreases. But the Zener diode maintains output voltage constant due to its property.

Limitations of Zener Voltage Regulator

There are a few limitations for a Zener voltage regulator. They are −

• It is less efficient for heavy load currents.
• The Zener impedance slightly affects the output voltage.

Hence a Zener voltage regulator is considered effective for low voltage applications. Now, let us go through the other types of voltage regulators, which are made using transistors.

Transistor Series Voltage Regulator

This regulator has a transistor in series to the Zener regulator and both in parallel to the load. The transistor works as a variable resistor regulating its collector emitter voltage in order to maintain the output voltage constant. The figure below shows the transistor series voltage regulator.

With the input operating conditions, the current through the base of the transistor changes. This effects the voltage across the base emitter junction of the transistor $V_{BE}$. The output voltage is maintained by the Zener voltage $V_Z$ which is constant. As both of them are maintained equal, any change in the input supply is indicated by the change in emitter base voltage $V_{BE}$.

Hence the output voltage Vo can be understood as

$$V_O=V_Z+V_{BE}$$

Working of Transistor Series Voltage Regulator

The working of a series voltage regulator shall be considered for input and load variations. If the input voltage is increased, the output voltage also increases. But this in turn makes the voltage across the collector base junction $V_{BE}$ to decrease, as the Zener voltage $V_Z$ remains constant. The conduction decreases as the resistance across emitter collector region increases. This further increases the voltage across collector emitter junction VCE thus reducing the output voltage $V_O$. This will be similar when the input voltage decreases.

When the load changes occur, which means if the resistance of the load decreases, increasing the load current $I_L$, the output voltage $V_O$ decreases, increasing the emitter base voltage $V_{BE}$.

With the increase in the emitter base voltage $V_{BE}$ the conduction increases reducing the emitter collector resistance. This in turn increases the input current which compensates the decrease in the load resistance. This will be similar when the load current increases.

Limitations of Transistor Series Voltage Regulator

Transistor Series Voltage Regulators have the following limitations −

• The voltages $V_{BE}$ and $V_Z$ are affected by the rise in temperature.
• No good regulation for high currents is possible.
• Power dissipation is high.
• Power dissipation is high.
• Less efficient.

To minimize these limitations, transistor shunt regulator is used.

Transistor Shunt Voltage Regulator

A transistor shunt regulator circuit is formed by connecting a resistor in series with the input and a transistor whose base and collector are connected by a Zener diode that regulates, both in parallel with the load. The figure below shows the circuit diagram of a transistor shunt regulator.

Working of Transistor Shunt Voltage Regulator

If the input voltage increases, the $V_{BE}$ and $V_O$ also gets increased. But this happens initially. Actually when $V_{in}$ increases, the current $I_{in}$ also increases. This current when flows through RS, causes a voltage drop $V_S$ across the series resistor, which also gets increased with $V_{in}$. But this makes $V_o$ to decrease. Now this decrease in $V_o$ compensates the initial increase maintaining it to be constant. Hence $V_o$ is maintained constant. If the output voltage decreases instead, the reverse happens.

If the load resistance decreases, there should be decrease in the output voltage $V_o$. The current through the load increases. This makes the base current and collector current of the transistor to decrease. The voltage across the series resistor becomes low, as the current flows heavily. The input current will be constant.

The output voltage appears will be the difference between the applied voltage $V_i$ and the series voltage drop $V_s$. Hence the output voltage will be increased to compensate the initial decrease and hence maintained constant. The reverse happens if the load resistance increases.

IC Regulators

Voltage Regulators are now-a-days available in the form of Integrated Circuits (ICs). These are in short called as IC Regulators.

Along with the functionality like a normal regulator, an IC regulator has the properties like thermal compensation, short circuit protection and surge protection which are built into the device.

Types of IC regulators

IC regulators can be of the following types −

• Fixed Positive voltage regulators
• Fixed Negative voltage regulators
• Adjustable voltage regulators
• Dual-tracking voltage regulators

Let us now discuss them in detail.

Fixed Positive Voltage Regulator

The output of these regulators is fixed to a specific value and the values are positive, which means the output voltage provided is positive voltage.

The most used series is 7800 series and the ICs will be like IC 7806, IC 7812 and IC 7815 etc. which provide +6v, +12v and +15v respectively as output voltages. The figure below shows the IC 7810 connected to provide a fixed 10v positive regulated output voltage.

In the above figure, the input capacitor $C_1$ is used to prevent unwanted oscillations and the output capacitor $C_2$ acts as a line filter to improve transient response.

Fixed Negative Voltage Regulator

Serial Number Perspective Rectifier Regulator Chart

The output of these regulators is fixed to a specific value and the values are negative, which means the output voltage provided is negative voltage.

The most used series is 7900 series and the ICs will be like IC 7906, IC 7912 and IC 7915 etc. which provide -6v, -12v and -15v respectively as output voltages. The figure below shows the IC 7910 connected to provide a fixed 10v negative regulated output voltage.

Serial Number Perspective Rectifier Regulator Kit

In the above figure, the input capacitor $C_1$ is used to prevent unwanted oscillations and the output capacitor $C_2$ acts as a line filter to improve transient response.

Regulator Rectifier Motorcycle

Adjustable Voltage Regulators

An adjustable voltage regulator has three terminals IN, OUT and ADJ. The input and output terminals are common whereas the adjustable terminal is provided with a variable resistor which lets the output to vary between a wide range.

Serial Number Perspective Rectifier Regulator Replacement

The above figure shows an unregulated power supply driving a LM 317 adjustable IC regulator which is commonly used. The LM 317 is a three terminal positive adjustable voltage regulator and can supply 1.5A of load current over an adjustable output range of 1.25v to 37v.

Dual-Tracking Voltage Regulators

A dual-tracking regulator is used when split-supply voltages are needed. These provide equal positive and negative output voltages. For example, the RC4195 IC provides D.C. outputs of +15v and -15v. This needs two unregulated input voltages such as the positive input may vary from +18v to +30v and negative input may vary from -18v to -30v.

Regulator Rectifier Function

The above image shows a dual-tracking RC4195 IC regulator. The adjustable dual-tacking regulators are also available whose outputs vary between two rated limits.