• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

VoltCraft AT-400?

Brit01

Member
2008-07-04 10:35 am
Looking at a voltcraft transformer with outputs of 115 V~, 125V~, 230V~ or 240 VAC @400VA max.

Asking 50 USD used.

Would be good for projects.

so 400va/ 115 = 3.45 amps max?

Worth the purchase?

Does anyone know the make or had experiences with these?

I'm struggling with finding suitable tranformers here for different voltages.
 

bob91343

Member
2010-03-11 10:43 pm
I have no knowledge of that brand of transformer. However you can make comparisons easily by looking through Mouser or Digi-Key or Newark or Allied catalogs. See if the price is comparable, as well as the specifications. And of course make sure it can handle the 50 Hz supply if it needs to. Also verify if the transformer is isolation or autotransformer.

Your calculation is correct - VA is voltamperes.
 

Brit01

Member
2008-07-04 10:35 am
This is the manual:


 Introduction
Dear Customer,
In purchasing this Voltcraft® product, you have made a very good decision for
which we should like to thank you.
You have acquired an above-average quality product from a brand family which has
distinguished itself in the field of measuring, charging and network technology by
particular competence and permanent innovation.
With Voltcraft®, you will be equal to difficult tasks as an ambitious hobbyist just as
much as a professional user. Voltcraft® offers you reliable technology at an extraordinarily
favourable cost-performance ratio.
We are certain: your start with Voltcraft will at the same time be the commencement
of a long and profitable co-operation.
We wish you much enjoyment with your new Voltcraft® product!
Table of Contents
Introduction ..............................................................................................................12
Table of contents ......................................................................................................12
Intended use ............................................................................................................13
Safety instructions and warning information ............................................................14
Scope of delivery ......................................................................................................15
Operating elements (see fold-out page)....................................................................16
Starting operation......................................................................................................16
Connection ............................................................................................................16
Connection of a consumer ....................................................................................17
Servicing and cleaning ..............................................................................................17
Replacing the fuse ................................................................................................18
Trouble shooting ......................................................................................................18
Disposal ....................................................................................................................19
Technical data ..........................................................................................................19
13
Intended Use
The connection and operation of consumers with an operating voltage of either
115 V~, 125V~, 230V~ or 240 V~ to the appropriate sockets.
Depending on the input voltage, 115 V~, 125V~, 230V~ or 240 VAC, the pre-settable
output voltages are available on the earthing-pin socket (1).
Only 115V~ is pending at the US socket independent of the input voltage. This voltage
cannot be altered.
The power consumption of a connected consumer may not exceed 400 VA for type
AT-400, 1000VA for type AT-1000 or a of max. 1500 VA for type AT-1500. If this is
exceeded or a short takes place, it can lead to overloading and thus to destruction of
the series transformer.
An auto-transformer supplies the desired voltages. The outputs are electrically connected
with the input mains voltage.
The devices are constructed in accordance with protection class 1. They are only
licensed for connection to sockets with earthing and, depending on the adjustment
of the voltage selection switch at the input, with an alternating voltage of
115V/125V/230V and 240V~ /50-60Hz.
The in and outputs are secured by fuses.
Use in damp rooms or outdoors or under adverse ambient conditions is not permitted.
The following are unfavourable ambient conditions:
- wetness or excessive humidity
- dust or combustible gases, vapours or solvents
- strong vibration
Use other than that described above will damage the product and may involve other
risks such as short circuit, fire and electric shock etc. Do not change or modify any
part of the product. The safety instructions have to be observed at all times!
14
Safety instructions and danger warnings
The guarantee will expire in case of damage caused by failure to
comply with these instructions! We do not accept liability for
damage to property or injury to persons caused by mishandling or
non-compliance with the safety instructions.
This device left the factory in perfect condition in terms of safety engineering.
To maintain this status and ensure safe operation, you, as user, must comply with
the safety instructions and warnings contained in these instructions for use. The following
symbols must be observed:
Note! Read the instructions for use.
This equipment is CE-tested and complies with the EMC directive
89/336/EEC and the low-voltage directive 73/23/EEC.
Auto transformer; in/output electrically connected.
Earth connection; this screw may not be slackened.
? Electrical appliances and accessories should be kept out of the reach of children!
? In commercial institutions, the accident prevention regulations of the Employer?s
Liability Insurance Association for Electrical Systems and Operating Materials are
to be observed.
? In schools and training centres as well as at hobby and DIY workshops, the use of
power packs must be supervised by adequately trained personnel in a responsible
manner.
? For safety and licensing (CE) reasons, unauthorised conversion and/or modifications
to the product are not permitted.
? Do not expose the device to high temperatures, dampness or strong vibration or
excessive mechanical loads.
15
? Never touch the device or the plug with wet or moist hands. There is risk of a fatal
electric shock!
? Live components may be exposed if covers are opened or parts are removed
unless this can be done by hand.
? Before opening it, disconnect the device from all voltage sources.
? Do not switch the measuring instrument on immediately after having taken it from
a cold to a warm environment. Under adverse conditions, the resulting condensation
could destroy the device. Allow the device to reach room temperature before
switching it on.
? The device generates heat when operating; ensure that it is adequately ventilated.
Do not cover the ventilation apertures of the device!
? Only use fuses of the type and rated current specified. The use of repaired fuses is
not permitted.
? Make sure that the earth wire is not broken as, in the case of error, there could be
danger to life. Further, ensure that the insulation is neither damaged nor destroyed.
? The outputs of the series transformer are not electrically isolated from the mains
supply (auto transformer). Fatal risk can arise if the output voltage is contacted.
? Do not connect direct current (DC). The series transformer functions only with
alternating current (AC).
? If you have reason to assume that safe operation is no longer possible, immediately
take the device out of operation and secure it against inadvertent operation. It
can be assumed that risk-free operation is no longer possible if
- the device shows visible signs of damage
- the device no longer functions and
- has been stored for long periods under unfavourable conditions or
- has been subjected to considerable stress in transit.
? Observe also the safety instructions in the individual sections of these operating
instructions or in the operating instructions of the connected devices.
Scope of delivery
Series transformer
Operating instructions
16
Operating elements
(see fold-out page)
1 Output earthing socket (115V / 125V / 230V / 240V)
2 Fuse for output voltage, earthing socket (1)
3 Red signal display "polarity of mains plug incorrect?
4 Green signal display "polarity of mains plug OK?
5 115-V output US earthing socket
6 Voltage selection switch, output earthing socket (1)
7 Carrying grips
8 Voltage selection switch, input refrigerating device connection (9)
9 Refrigerating machine connection for mains cable
10 Fuse for input voltage
11 Fuse for output voltage, US earthing socket 115V (5)
Starting up operation
Before starting up operation, both the intended purpose of use
and the safety instructions and technical data are to be observed!
Mains connection:
? Make sure before connection that the change-over switch (8) is set correctly for
the input voltage. To switch it over, use a suitable screwdriver,
230V~ in Germany and most other European countries or
115V~ / 125V~ /240V~ in some of the other countries (non-European).
? Connect the optional earthing power cable to the mains connector jack (9) on the
device. Make sure it is plugged properly.
? Connect the mains cable to an earthed mains socket with protective earthing. The
series transformer is now in operation.
Observe the signal displays on the front.
? If the mains plug is plugged in correctly, the green display "L" (4) will light up.
17
? If, on the other hand, the red display "N" (3) lights up, you have to turn the mains
plug 180° in the socket (wall socket). This is an additional protective measure to
prevent risks when defective devices are connected.
If both signal displays light up, this is indication of a missing earth
wire. Do not put the series transformer into operation and have
the mains socket checked by a specialist. In case of error, a broken
earthing wire can be fatal!
Connecting a consumer
Independent of the selection of input voltage, the following output voltages are
always pending at the output sockets:
? earthing socket (1) optionally 115V~ / 125V~ / 230V~ / 240V~ (adjustable by means
of the voltage selection switch (6); use a suitable screwdriver for the change-over)
? US earthing socket (5) 115V~ not adjustable
Connect your consumer to the appropriate output socket (1 or 5) using a suitable
mains cable.
Make sure that the insulation of the mains cables is not damaged.
Make sure that the consumers are switched off when being
connected to the series transformer. Sparks may be generated
when a switched-on consumer is connected to the jacks. This
may damage the terminal screw connectors as well as the
connected cables.
If the series transformer is no longer required, disconnect it from
the mains.
During a longer period of operation under nominal load, the surface
of the housing will heat up. Therefore, make sure that there is
adequate ventilation of the device and, to avoid any damage,
never operate it when partly or completely covered.
Servicing and cleaning
The devices are maintenance-free apart from the replacement of fuses and occasional
cleaning. To clean the device, switch of the power and take a clean, lint-free, antistatic
and dry cloth without any abrasive or chemical agents or detergents containing
solvents.
18
Replacing the fuse
If the series transformer can no longer be put into operation (no signal display (3 or 4)
lights up), the mains fuse (10) is presumably defective.
If there is no voltage pending at the earthing socket (1) although the signal display (3
or 4) lights up), the mains fuse (2) is presumably defective.
If there is no voltage pending at the US earthing socket (5) although the signal display
(3 or 4) lights up), the mains fuse (11) is presumably defective.
Proceed as follows to replace the mains fuse for the models AT-400 or AT-1000:
? Remove all connection and mains cables from the device.
? Release the bayonet lock of the appropriate fuse bracket exerting slight pressure
in the direction of the arrow (a quarter, anticlockwise revolution).
? Replace the defective fuse with a new fine-wire fuse (5 x 20 mm) of the same type
and rated current. You can find the fuse data in the technical data.
? Insert the fuse bracket and lock it in the reverse order.
? The series transformer can be put into operation again.
Make sure that only fuses of the type stated and rated current
specified are used as a replacement. The use of repaired fuses or
bridging the fuse bracket is not permitted.
The AT-1500 model has automatic fuses instead of melting fuses. Proceed as follows
to switch the device on again:
? Remove all connection and mains cables from the device.
? Press in the pin on the automatic fuse until it snaps in properly.
? The series transformer can be put into operation again.
Troubleshooting
By purchasing the series transformer, you have acquired a product which is reliable
and operationally safe.
However, problems and malfunctions may occur nevertheless.
19
For this reason we wish to describe here how you can eliminate potential disturbances
yourself:
Observe the safety instructions at all times!
Fault Possible cause
The remote control Are the control lamps on the device alight (3 or 4)?
does not function Check the mains voltage (you may also wish to check
the mains fuse in the device or the electric cut-out
device in the distribution for the building).
Check the technical safety of the device regularly, e.g. check for damage to the
housing etc.
Any other repair work may only be carried out by qualified experts
familiar with the dangers involved as well as with the relevant
regulations. Unauthorised modification or repairs on or inside the
device will lead to the lapse of the warranty.
Disposal
If the product is no longer functional and can no longer be repaired,
dispose of it in accordance with the relevant statutory regulations.
Technical data
AT-400 AT-1000 AT-1500
Operating voltage 115V~ / 125V~ /240V~ (+/-10%) 50/60Hz
Connection output max. 400VA max. 1000VA max. 1500VA
Fuses: 3x T4A/250V 3x T10A/250V 3x T15A/250V
5 x 20 (mm) 5 x 20 (mm) Automatic fuses
Output voltage 115V~ / 125V~ 230V/~ 240V~ (+/-10%) 50/60Hz
Working temperature 0°C (+40°C to 80%)
at a max. humidity of <80%, non-condensing
Dimensions 225 x 135 x 240 305 x 135 x 240 305 x 135 x 240
(W x H x T in mm)
Earth approx. 3.5 kg approx. 5.3 kg approx. 7.4 kg
20
 

bob91343

Member
2010-03-11 10:43 pm
Wow after reading all those precautions, one must be very brave to plug in this device! It is indeed an autotransformer and so offers no isolation. It will work at 50 Hz so that's not a problem.

So if all you are seeking is a way to operate variously rated equipment from whatever mains you have available, this will work. I can't testify as to the fairness of the price; you will have to check into that yourself.
 

Brit01

Member
2008-07-04 10:35 am
Thanks for the heads up guys. So no isolation. Not good.

I'll look out for the standard trannies from now on.

Just picked up 4 x 28v @ 3 amps.
Drives 4 x 6080/6AS7 heaters nicely in series. I get 25 volts after the sag and it gets just warm. 27 USD for the 4.

Also tomorrow is arriving 350-0-350/5v/6v @ 6amps.
15 USD :D:D:D