VS1 VOX Voice Activated Switch Kit


Ramsey Electronics Model No.


 Turns ON when you talk  Turns OFF when you stop  Uses any type of microphone  Compact & easy to install  Operates on 9 - 12 volts DC Ramsey Customer Use Only Not For The VS1 provides quality components and a compact printed circuit board that makes it a snap to “turn on” a multitude of devices, from HAM transmitters and amps to tape recorders or clandestine listening equipment......HAVE FUN!


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 FM10, FM25B FM Stereo Transmitters  FM100B Professional FM Stereo Transmitter  AM1, AM25 Transmitters


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RAMSEY MINI-KITS Many other kits are available for hobby, school, scouts and just plain FUN. New kits are always under development. Write or call for our free Ramsey catalog.

VS1 Voice Activated Switch Ramsey Electronics publication No. VS1 Rev. 1.2 This Printing: August 2010


COPYRIGHT 2006-2010 by Ramsey Electronics, LLC 590 Fishers Station Drive, Victor, New York 14564. All rights reserved. No portion of this publication may be copied or duplicated without the written permission of Ramsey Electronics, LLC Printed in the United States of America.

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Ramsey Publication No. VS1 Manual Price Only $5.00


Ramsey Customer Use Only Not For

TABLE OF CONTENTS Introduction to the VS1 ..................................... 4 VS1 Circuit Description ..................................... 4 “Learn-As-You-Build” Kit Assembly ................... 4 Parts List ........................................................... 5 VS1 Parts Layout Diagram ................................ 5 Assembly Steps ................................................. 6 VS1 Schematic................................................. 10 Ramsey Kit Warranty ....................................... 11


RAMSEY ELECTRONICS, LLC 590 Fishers Station Drive Victor, New York 14564 Phone (585) 924-4560

Fax (585) 924-4555 www.ramseykits.com

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INTRODUCTION TO THE VS1 The VS1 is a universal voice-operated-switch (VOX) module which may be used in any application where VOX operation is desired. It may be used with virtually any type of microphone. The circuit itself draws only 10 mA at 9 volts DC and will directly switch low voltage loads up to 100 mA. Numerous small and inexpensive relays are available to permit switching of higher voltage and current. The VS1 VOX may be used to control ham radio transmitters, CB transceivers, and similar equipment for other radio services. In addition, it can be used to control tape recorders or any other device for which you envision voice-operated switching. HOW IT WORKS: The dual op amps of the LM358 IC amplify the microphone signal. R2,R3 and C2 configure the LM358 for operation from a single voltage supply. The output from the op amp is rectified to DC by the diodes D1 and D2. The VOX delay (length of time that the transistor Q3 is switched on) is determined by C4 and R7. The 220K ohm value for R7 produces a VOX delay quite useful for most applications. A 500K or 1 megohm trimmer in place of R7 permits a wide range of VOX delay settings. Transistors Q1 and Q2 provide enough drive for efficient switching by Q3. RAMSEY Learn-As-You-Build KIT ASSEMBLY  Use a 25-watt soldering pencil with a clean, sharp tip.  Use only rosin-core solder intended for electronics use.  Use bright lighting; a magnifying lamp or bench-style magnifier may be helpful.  Do your work in stages, taking breaks to check your work. Carefully  brush away wire cuttings so they don't lodge between solder connections. We have a two-fold "strategy" for the order of the following kit assembly steps. First, we install parts in physical relationship to each other, so there's minimal chance of inserting wires into wrong holes. Second, whenever possible, we install in an order that fits our "Learn-As-You Build" Kit building philosophy. This entails describing the circuit that you are building instead of just blindly installing components. We hope that this will not only make assembly of our kits easier, but help you to understand the circuit you’re constructing. For each part, our word "Install" always means these steps: Ramsey Customer Use Only Not For Publication

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1. Pick the correct part value to start with. 2. Insert it into the correct PC board location. 3. Orient it correctly, follow the PC board drawing and the written directions for all parts - especially when there's a right way and a wrong way to solder it in. (Diode bands, electrolytic capacitor polarity, transistor shapes, dotted or notched ends of IC's, and so forth.) 4. Solder all connections unless directed otherwise. Use enough heat and solder flow for clean, shiny, completed connections.  4 4.7 or 10uF electrolytic capacitors (C1, C2, C3, C4)  4 1K ohm resistors [brown-black-red] (R4, R5, R10, R11)  5 10K ohm resistors [brown-black-orange] (R2, R3, R6, R8, R9)  1 220K ohm resistor [red-red-yellow] (R7) Ramsey er Use  1 1 Megohm resistor [brown-black-green] (R1)  2 NPN transistors [marked 2N3904] (Q1, Q2)  1 PNP transistor [marked 221334] (Q3)  1 LM358 8-pin DIP Dual Operational Amp IC (U1) VS1 PARTS LIST 


 2 1N4148 diode (D1, D2)  1 VS1 printed circuit board Cust



For Publication

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ASSEMBLY OF THE VS1 Notice that all resistors are installed vertically. Since most of the resistors are either of two values; 1K (brown-black-red) or 10K (brown-black-orange ), be sure not to mix them up. Only four capacitors are used, all small electrolytics; be sure to observe correct polarity . While the PC board can be quickly "stuffed" in any order you like by referring to the parts layout diagram, we suggest you use the following step-by-step assembly directions.  1. Install the LM358 IC. If you prefer to use a socket, install it with the same care as the IC itself. Be sure that the notched end of the chip is oriented as illustrated!  2. Install electrolytic capacitor C1. Observe proper polarity.  3. Install C2, observing correct polarity.  4. Install R1, 1 megohm [brown-black-green].  5. Install R3, 10K [brown-black-orange].  6. Install R4, 1K [brown-black-red].  7. Install R5, 1K [brown-black-red].  8. Install diode D1. Be sure that the banded (cathode) end is oriented correctly.  9. Install R2, 10K [brown-black-orange].  10. Install C3, observing correct polarity.  11. Install diode D2, being careful to orient the band correctly. Ramsey Customer Use Only Not For  12. Install R6, 10K [brown-black-orange].  13. Install C4, observing correct polarity.  14. Install R7, 220K [red-red-yellow].  15. The position for Q3 (marked 221-334), the PNP switching transistor is obvious at the end of the PC board. Identify and install it now so that it will not be mixed up with Q1 or Q2. Point the flat side as shown on the parts layout diagram. Publication

 16. Install Q1, 2N3904 NPN transistor.  17. Install R10, 1K [brown-black-red].  18. Install Q2, 2N3904 NPN transistor.

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 19. Install R9, 10K [brown-black-orange].  20. Install R11, 1K [brown-black-red].  21. Install R8, 10K [brown-black-orange]. FINAL CONNECTIONS AND OPERATION  Connect RED hookup wire to point D for ( + ) DC.  Connect BLACK hookup wire to point C for ground ( - ) DC.

The VS1 is designed for optimum operation at 9VDC but it also may be operated from 12 volts. If you do not like its performance (sensitivity and delay time) at 12 volts, the addition of a simple 3-terminal voltage regulator such as a 7808 will provide a reduced and regulated voltage for the VS1. For satisfactory 6-volt operation, the value of R7 will need to be adjusted.  Unless a microphone cartridge is to be mounted at the edge of the PC board itself, use miniature shielded wire for the microphone connections at A and B. Point A is the "hot" side. Connect the shield to Point B. For the simplest first test, connect a voltmeter to points E (+) and F (-). When you speak into the microphone, you should get a voltage reading fairly close to the supply voltage. If you make a brief sound, the output will be powered for about one second. If you speak steadily, the circuit will remain powered without interruption, unless there are long pauses (See Application Notes below regarding VOX Delay adjustment). The most practical output device to connect at points E and F is a low-current 6 or 12 volt DC relay. Many suitable SPST, SPDT and DPDT relays are available at Radio Shack. Ramsey Customer Use Only Not For


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APPLICATION NOTES The length of VOX delay is controlled by the values of C4 and R7. A 1 megohm trimmer in place of the 220K R7 resistor will provide excellent delay range. Another factor which you may wish to control is "VOX Gain", which is different from "Mike Gain" of the transmitter or other device controlled by the VS1 VOX circuit. A simple gain control hookup is indicated as optional on the schematic diagram. Another feature of VOX circuits is called "anti-trip" or "anti-VOX". This is useful in communications equipment to prevent the signals or noise coming from the speaker from tripping the VOX. Effective anti-vox requires additional differential amplifier or comparator circuitry that is beyond the purpose of the simple VS1. To minimize unwanted tripping of your VS1, keep both the suggested VOX gain control and speaker volume as low as possible or maximize the distance between the radio's speaker and the VS1 microphone. If controlling a tape recorder motor is your intended application, test the motor's current requirement in mA with your VOM. If it is less than that 100 mA, the Q3 transistor switch can control the motor directly. If you have any hesitation, use a relay. Finally, we note that some customers have bought the VS1 assuming they can use it to switch a device such as a computer or appliance or lamp on and off by voice command or other sound. Obviously, such "latching" or "toggling" functions are not the primary applications for which the output circuit of the VS1 was designed. Can it be done? Yes, if you would like to explore the capabilities of flip-flop IC's such as the 4013. For example, study how our TS1 Touch Switch works. A simple latch circuit can be made with a relay as illustrated, but you would have to turn it off manually, not by sound. In "rigging up" the VS1 to control circuits not discussed in this booklet, particularly any AC-line powered device such as a lamp, please remember that the direct switching output is intended only for DC loads under 30 volts and under 100 mA. When wiring a relay to control other loads, particularly 120 Volt AC circuits, please observe all standard electrical safety precautions. Ramsey Customer Use Only Not For

+9V Publication

Momentary OFF switch (normally closed) To Load




DPDT or DPST Relay

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CONCLUSION We sincerely hope that you will enjoy the use of this Ramsey product. As al- ways, we have tried to compose our manual in the easiest, most “user friendly” format that is possible. As our customers, we value your opinions, comments, and additions that you would like to see in future publications. Please submit comments or ideas to: OPTIONAL: VOXSensitivityControl Ramsey Customer Use Only Not For Ramsey Electronics LLC Attn. Hobby Kit Department 590 Fishers Station Drive Victor, NY 14564 or email us at: techsupport@ramseyelectronics.com Ramsey has a whole line of little "problem-solver" kits like this, including general purpose timers, audio amplifiers, touch switches and tone decoders - all at unbeatable prices. Call or write for our catalog! Publication - + 9VDC

And once again, thanks from the folks at Ramsey!

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Ramsey Customer Use Only Not For


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VS1  11 Please understand that our Tech Support Group personnel are not volunteers! They are a dedicated group of highly trained technicians each configured with a very properly equipped test bench. Upon receipt of a repair, the setup, testing, diagnosis, repair, paperwork, and repacking of your kit requires nearly an hour of their time regardless of the size or complexity of the kit! The minimum repair fee represents ½ hour Tech Support time at $50/hour USD. We try to keep all kit repairs within the realm of the $25 flat rate whenever possible…and trust us; we exceed that time spent on most kits received more often than not! 7. CONTACT INFORMATION AND RETURN ADDRESS: Technical Questions Product Repair & Returns RAMSEY ELECTRONICS, LLC Attn: Tech Support 590 Fishers Station Drive Victor, NY 14564 585-924-4560; 585-924-4886 Fax techsupport@ramseyelectronics.com RAMSEY ELECTRONICS, LLC Attn: Repairs 590 Fishers Station Drive Victor, NY 14564 585-924-4560; 585-924-4886 Fax repairs@ramseyelectronics.com Publication 1. GENERAL: Notice that this is not a "fine print" warranty. We want you to understand your rights and ours too! All Ramsey kits will work if assembled properly. The very fact that your kit includes this new manual is your assurance that prior to release of this kit, a varied group of knowledgeable people have assembled this kit from scratch using this manual. During this process, changes and additions are noted by each assembler and integrated into the final version of the manual…which you have! If you need help, please read through your manual carefully, all information required to properly build and test your kit is contained within the pages! However, customer satisfaction is our goal, so in the event that you do have a problem, please note the following: 2. DEFECTIVE PARTS: It's always easy to blame a part for a problem in your kit. Before you conclude that a part may be bad, thoroughly check your work. Today's semiconductors and passive components have reached incredibly high reliability levels, and it’s sad to say that our human construction skills have not! But on rare occasions a sour component can slip through. All of our kit parts carry the Ramsey Electronics Warranty that they are free from defects for a full ninety (90) days from the date of purchase. Defective parts will be replaced promptly at our expense. If you suspect any part to be defective, please mail it to our factory for testing and replacement. Please send only the defective part(s), not the entire kit. The part(s) MUST be returned to us in suitable condition for testing. Please be aware that testing can usually determine if the part was truly defective or damaged by assembly or usage. Don't be afraid of telling us that you “damaged it” or “burned it out”, we're all human and in most cases, replacement parts are very reasonably priced. Remember, our goal for over three decades is to have a happy customer, and we’re here to work WITH you, not AGAINST you! 3. MISSING PARTS: Before assuming a part value is missing, check the parts listing carefully to see if it is a critical value such as a specific coil or IC, or whether a RANGE of values is suitable for the component (such as a "100 to 500 uF capacitor"). Often times, common sense will solve a mysterious missing part problem. If you're missing five 10K ohm resistors and received five extra 1K resistors, you can pretty much be assured that the “1K ohm” resistors are actually the “missing” 10 K parts ("Hum-m-m, I guess the orange band really does look red!") Ramsey Electronics project kits are packed with pride in the USA by our own staff personnel. While separate QC checks are made on all product kits, we too are human, and once in a great while there is a chance something can get through those checks! If you believe we packed an incorrect part or omitted a part clearly indicated in your assembly manual for your Ramsey kit, please contact us with information on the part you need. Contact our Repair Department via telephone, email or writing. Please have your invoice number and date of purchase handy. 4. REFUNDS: All Ramsey products, kit or factory assembled units have an unconditional 10 day (from the date of purchase) return policy to examine our products. If you are not satisfied for any reason, you may return your unassembled kit with all the parts and instructions, or your factory assembled and tested product, together with your proof of purchase to the factory for a full refund less shipping. The return package should be packed securely. Insurance and tracking is highly recommended. A reminder, this applies to unassembled kits. They must be in the same new condition as received, not partially assembled! Assembled kits cannot be returned for credit. No RMA’s are required; simply return to Ramsey Electronics LLC, Attn: Product Returns, 590 Fishers Station Drive, Victor, NY, 14564. If you have any questions, please contact us at 585-924-4560. 5. FACTORY REPAIR OF ASSEMBLED KITS: Most of us at Ramsey are technically oriented and we do realize that things happen! Even following the best practices, with all of the best intentions, there is that chance that your kit doesn’t work when you have completed it. Each manual goes into detailed troubleshooting based on the specific kit to help you troubleshoot the problem. We have found that 95% of returned kits involved wrongly installed components (wrong part or backwards polarity). This section of the warranty assumes you have gone through all those steps, and have now reached the point that you need to send it back. To qualify for factory repair of customer assembled kits, the following conditions apply: 1. Kits must not be assembled with acid solder flux 2. Kit boards or circuits must not be modified in any manner from the version received 3. Kits must be fully assembled, not partially assembled. Our warranty does not include “finishing” your kit! 4. Must include a full description of the problem encountered including the troubleshooting steps you have already done. 5. Must not include non-standard, non-Ramsey accessories, cases, enclosures, knobs, etc. or any batteries. 6. Must include the minimum repair fee of $25 USD in the form of check, money order or credit card authorization. 7. Ramsey Electronics, LLC reserves the right to refuse any repair due to excessive errors in construction methods. 8. If, due to customer construction methods, the repair is estimated to exceed the minimum flat rate, Ramsey Electronics, LLC will contact the customer to discuss the repairs needed and to receive authorization and payment for repair prior to repair. 9. In the unlikely case that a defective part is found to be the cause of the problem, the repairs will be made at no-charge to the customer, and any payments received for repair will be returned or credited back to the customer. 10. Properly pack your kit, insure the package, and use a carrier that can be tracked. Ramsey Electronics, LLC is not responsible for any loss or damage in shipment. Send the package together with your repair fee to the return address below. No RMA is required. 6. FACTORY REPAIR FEES: Ramsey Customer Use Only Not For

TABLE OF CONTENTS Introduction to the VS1 ..................................... 4 VS1 Circuit Description ..................................... 4 “Learn-As-You-Build” Kit Assembly ................... 4 Parts List ........................................................... 5 VS1 Parts Layout Diagram ................................ 5 Assembly Steps ................................................. 6 VS1 Schematic................................................. 10 Ramsey Kit Warranty ....................................... 11

Manual Price Only: $5.00 Ramsey Publication No. VS1 Assembly and Instruction manual for: RAMSEY MODEL NO. VS1 VOICE SWITCH KIT Ramsey Customer Use Only Not For REQUIRED TOOLS  Soldering Iron  Thin Rosin Core Solder  Needle Nose Pliers  Small Diagonal Cutters ADDITIONAL SUGGESTED ITEMS  Helping Hands Holder for PC Board/Parts  Technician’s Tool Kit  Desoldering Braid

TOTAL SOLDER POINTS 25 ESTIMATED ASSEMBLY TIME Beginner .............. 0.8 hrs Intermediate......... 0.5 hrs Advanced............. 0.3 hrs Publication


ELECTRONICS, LLC 590 Fishers Station Drive Victor, New York 14564 Phone

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(585) 924-4560 (585) 924-4555


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