An electroscope is the instrument used to detect charged bodies. Here, an electronic version of the scope that is more sensitive as compared to its conventional counterpart and which helps indicate the polarity of charge has been described. This circuit consumes very low quiescent power and reliably indicates charge induction and detection. The polarity of charge is indicated through Leeds (green LED indicates positive and red LED negative). In this project report, the detailed circuit diagram of the electronic electroscope has been given In which dual timer ICE and two input
AND gate ICC COCCID have been used followed by Its working in which few observations with regards to the glowing of the Leeds have been made. This Is followed by the explicit mention of the applications of electronic electroscope. A list of Important components that form an Integral part of this project topic has been made. 1 . Illumination In most experiments dealing with static electricity, an electroscope Is required to Indicate the presence of small amounts of positive or negative charge In laboratories, gold leaf electroscopes being one of them.
However, these gold leaf electroscopes ay be too delicate and costly for the average home experiments. An alternative to this is the electronic electroscope which is not only rugged and inexpensive,but is as sensitive as the gold leaf electroscope. An electronic version of the scope is more sensitive as compared to its conventional counterpart and helps indicate the polarity of charge in any charged body. In Section 2, the circuit diagram as well as the PC layout of the electronic electroscope has been given. In Section 3, the working of the circuit has been explained In detail along with some important observation.
Section 4 contains the list of components that are essential for building the circuit. Section 5 enlists few applications of the electronic electroscope. In Section 6, relevant conclusions have been drawn. PC Layout: 3. Working: The diodes DO and DO (1 NANNY) help determine the direction of current flow, removing certain shortcomings of the circuit. (These prevent the capacitor of the opposite arm from charging when the object is withdrawn quickly. ) Even though diode in series with capacitor C is reverse biased, the current through it is adequate to charge capacitor C.
Thus capacitor C gets charged with respect to the ground and the input voltage of gate IN goes high. This makes the gate output low and transistor TO conducts to light up the green LED. The process is similar during negative charge detection. Here transistor TO conducts to light up the red LED. When a negatively charged object is brought near the detecting wire, it also affects the positive-detecting wire. The negatively charged object pushes the electrons in the positive-detecting wire towards its input capacitor and the wire becomes negatively charged with respect to the ground.
These electrons leak through the gate input into the other parts of the circuit. When the negatively charged object is withdrawn, the positive-detecting side having lost electrons (detecting wires and the capacitor) appears to be positively not conduct heavily to return the electrons immediately. In this case, the charge developed across the capacitor takes a long time to decay and the gate becomes locked. To overcome this problem, two monosyllable multivariate built around ICC(A) and ICC(B) have been incorporated for each arm.
The high output of monosyllable ICC(B) horst capacitor C to the ground for a specific time as soon as the output of the negative-sensing gate (NO) goes from high to low. Similarly, the high output of ICC(A) charges capacitor CLC for a specific time as soon as the output of the positive-sensing gate (IN) goes from low to high. A similar arrangement is provided for both the positive- and negative-detecting sides. So when a positively charged object is withdrawn, the negative-charge- detecting input capacitor is shorted. The monosyllables prevent locking of any of the two gates and allow the scope to function smoothly.
Some of the observations made are as follows: The circuit achieves quiescent state I. E. , both Leeds go off in the absence of a newly charged object. The normal positive charge on a person was detected. Two bodies rubbed against each other had consistent opposite charges. The Leeds glow for a sufficiently long time and then go off (I. E. , a balance is set up with the external potential difference). When a positively charged body is brought near the detector wires, the green LED glows. When a negatively charged body is used, the red LED glows. 4.
Component List: Components Value Quantity dual timer 56 quad 2-input AND gate COCCID 1 no transistor BOCCE 2 nose BOCCE resistor 1 MOM 4. MOM kick capacitor loop F 0. 1 OF 4 nose 1 POOP diode 1 NANNY red color LED green color dc power supply metal wires 5. Application: It is possible to use the scope as a direct charge detector within limits by bringing the corresponding plates (or Just the lead) in direct contact with the point of charge accumulation in a circuit. The sensitivity can be increased to some extent by decreasing the values of capacitors CLC and C.
Electric charge can build up on a spacecraft when it is orbiting Earth or traveling n space. Excess charge build up is dangerous to a spacecraft’s delicate electronics, and can be harmful to astronauts on space walks. The electronic electroscope can be used to detect this excess electric charge on the spacecraft.